1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
48 static tree pfn_from_ptrmemfunc (tree);
49 static tree delta_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int,
52 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
53 static tree rationalize_conditional_expr (enum tree_code, tree,
55 static int comp_ptr_ttypes_real (tree, tree, int);
56 static bool comp_except_types (tree, tree, bool);
57 static bool comp_array_types (const_tree, const_tree, bool);
58 static tree pointer_diff (tree, tree, tree);
59 static tree get_delta_difference (tree, tree, bool, bool);
60 static void casts_away_constness_r (tree *, tree *);
61 static bool casts_away_constness (tree, tree);
62 static void maybe_warn_about_returning_address_of_local (tree);
63 static tree lookup_destructor (tree, tree, tree);
64 static int convert_arguments (int, tree *, tree, tree, tree, int,
67 /* Do `exp = require_complete_type (exp);' to make sure exp
68 does not have an incomplete type. (That includes void types.)
69 Returns the error_mark_node if the VALUE does not have
70 complete type when this function returns. */
73 require_complete_type (tree value)
77 if (processing_template_decl || value == error_mark_node)
80 if (TREE_CODE (value) == OVERLOAD)
81 type = unknown_type_node;
83 type = TREE_TYPE (value);
85 if (type == error_mark_node)
86 return error_mark_node;
88 /* First, detect a valid value with a complete type. */
89 if (COMPLETE_TYPE_P (type))
92 if (complete_type_or_else (type, value))
95 return error_mark_node;
98 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
99 a template instantiation, do the instantiation. Returns TYPE,
100 whether or not it could be completed, unless something goes
101 horribly wrong, in which case the error_mark_node is returned. */
104 complete_type (tree type)
106 if (type == NULL_TREE)
107 /* Rather than crash, we return something sure to cause an error
109 return error_mark_node;
111 if (type == error_mark_node || COMPLETE_TYPE_P (type))
113 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
115 tree t = complete_type (TREE_TYPE (type));
116 unsigned int needs_constructing, has_nontrivial_dtor;
117 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
120 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
122 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
123 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
125 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
126 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
129 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
130 instantiate_class_template (TYPE_MAIN_VARIANT (type));
135 /* Like complete_type, but issue an error if the TYPE cannot be completed.
136 VALUE is used for informative diagnostics.
137 Returns NULL_TREE if the type cannot be made complete. */
140 complete_type_or_else (tree type, tree value)
142 type = complete_type (type);
143 if (type == error_mark_node)
144 /* We already issued an error. */
146 else if (!COMPLETE_TYPE_P (type))
148 cxx_incomplete_type_diagnostic (value, type, DK_ERROR);
155 /* Return truthvalue of whether type of EXP is instantiated. */
158 type_unknown_p (const_tree exp)
160 return (TREE_CODE (exp) == TREE_LIST
161 || TREE_TYPE (exp) == unknown_type_node);
165 /* Return the common type of two parameter lists.
166 We assume that comptypes has already been done and returned 1;
167 if that isn't so, this may crash.
169 As an optimization, free the space we allocate if the parameter
170 lists are already common. */
173 commonparms (tree p1, tree p2)
175 tree oldargs = p1, newargs, n;
179 len = list_length (p1);
180 newargs = tree_last (p1);
182 if (newargs == void_list_node)
191 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
196 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
198 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
200 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
203 else if (! TREE_PURPOSE (p1))
205 if (TREE_PURPOSE (p2))
207 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
215 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
217 if (TREE_VALUE (p1) != TREE_VALUE (p2))
220 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
223 TREE_VALUE (n) = TREE_VALUE (p1);
231 /* Given a type, perhaps copied for a typedef,
232 find the "original" version of it. */
234 original_type (tree t)
236 int quals = cp_type_quals (t);
237 while (t != error_mark_node
238 && TYPE_NAME (t) != NULL_TREE)
240 tree x = TYPE_NAME (t);
241 if (TREE_CODE (x) != TYPE_DECL)
243 x = DECL_ORIGINAL_TYPE (x);
248 return cp_build_qualified_type (t, quals);
251 /* T1 and T2 are arithmetic or enumeration types. Return the type
252 that will result from the "usual arithmetic conversions" on T1 and
253 T2 as described in [expr]. */
256 type_after_usual_arithmetic_conversions (tree t1, tree t2)
258 enum tree_code code1 = TREE_CODE (t1);
259 enum tree_code code2 = TREE_CODE (t2);
262 /* FIXME: Attributes. */
263 gcc_assert (ARITHMETIC_TYPE_P (t1)
264 || TREE_CODE (t1) == VECTOR_TYPE
265 || UNSCOPED_ENUM_P (t1));
266 gcc_assert (ARITHMETIC_TYPE_P (t2)
267 || TREE_CODE (t2) == VECTOR_TYPE
268 || UNSCOPED_ENUM_P (t2));
270 /* In what follows, we slightly generalize the rules given in [expr] so
271 as to deal with `long long' and `complex'. First, merge the
273 attributes = (*targetm.merge_type_attributes) (t1, t2);
275 /* If one type is complex, form the common type of the non-complex
276 components, then make that complex. Use T1 or T2 if it is the
278 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
280 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
281 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
283 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
285 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
286 return build_type_attribute_variant (t1, attributes);
287 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
288 return build_type_attribute_variant (t2, attributes);
290 return build_type_attribute_variant (build_complex_type (subtype),
294 if (code1 == VECTOR_TYPE)
296 /* When we get here we should have two vectors of the same size.
297 Just prefer the unsigned one if present. */
298 if (TYPE_UNSIGNED (t1))
299 return build_type_attribute_variant (t1, attributes);
301 return build_type_attribute_variant (t2, attributes);
304 /* If only one is real, use it as the result. */
305 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
306 return build_type_attribute_variant (t1, attributes);
307 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
308 return build_type_attribute_variant (t2, attributes);
310 /* Perform the integral promotions. */
311 if (code1 != REAL_TYPE)
313 t1 = type_promotes_to (t1);
314 t2 = type_promotes_to (t2);
317 /* Both real or both integers; use the one with greater precision. */
318 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
319 return build_type_attribute_variant (t1, attributes);
320 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
321 return build_type_attribute_variant (t2, attributes);
323 /* The types are the same; no need to do anything fancy. */
324 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
325 return build_type_attribute_variant (t1, attributes);
327 if (code1 != REAL_TYPE)
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location,
401 tsubst_flags_t complain)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location,
437 if (complain & tf_error)
438 permerror (input_location, "%s between distinct pointer types %qT and %qT "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 /* If the original types were pointers to members, so is the
448 if (TYPE_PTR_TO_MEMBER_P (t1))
450 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
451 TYPE_PTRMEM_CLASS_TYPE (t2))
452 && (complain & tf_error))
453 permerror (input_location, "%s between distinct pointer types %qT and %qT "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 result_type = build_pointer_type (result_type);
462 /* Merge the attributes. */
463 attributes = (*targetm.merge_type_attributes) (t1, t2);
464 return build_type_attribute_variant (result_type, attributes);
467 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
468 ARG1 and ARG2 are the values with those types. The LOCATION is a
469 string describing the current location, in case an error occurs.
471 This routine also implements the computation of a common type for
472 pointers-to-members as per [expr.eq]. */
475 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
476 const char* location, tsubst_flags_t complain)
483 If one operand is a null pointer constant, the composite pointer
484 type is the type of the other operand. */
485 if (null_ptr_cst_p (arg1))
487 if (null_ptr_cst_p (arg2))
494 If one of the operands has type "pointer to cv1 void*", then
495 the other has type "pointer to cv2T", and the composite pointer
496 type is "pointer to cv12 void", where cv12 is the union of cv1
499 If either type is a pointer to void, make sure it is T1. */
500 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
508 /* Now, if T1 is a pointer to void, merge the qualifiers. */
509 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
514 if (TYPE_PTRFN_P (t2) && (complain & tf_error))
515 pedwarn (input_location, OPT_pedantic, "ISO C++ forbids %s "
516 "between pointer of type %<void *%> and pointer-to-function",
519 = cp_build_qualified_type (void_type_node,
520 (cp_type_quals (TREE_TYPE (t1))
521 | cp_type_quals (TREE_TYPE (t2))));
522 result_type = build_pointer_type (result_type);
523 /* Merge the attributes. */
524 attributes = (*targetm.merge_type_attributes) (t1, t2);
525 return build_type_attribute_variant (result_type, attributes);
528 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
529 && TREE_CODE (t2) == POINTER_TYPE)
531 if (objc_compare_types (t1, t2, -3, NULL_TREE))
535 /* [expr.eq] permits the application of a pointer conversion to
536 bring the pointers to a common type. */
537 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
538 && CLASS_TYPE_P (TREE_TYPE (t1))
539 && CLASS_TYPE_P (TREE_TYPE (t2))
540 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
543 class1 = TREE_TYPE (t1);
544 class2 = TREE_TYPE (t2);
546 if (DERIVED_FROM_P (class1, class2))
547 t2 = (build_pointer_type
548 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
549 else if (DERIVED_FROM_P (class2, class1))
550 t1 = (build_pointer_type
551 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
554 if (complain & tf_error)
555 error ("%s between distinct pointer types %qT and %qT "
556 "lacks a cast", location, t1, t2);
557 return error_mark_node;
560 /* [expr.eq] permits the application of a pointer-to-member
561 conversion to change the class type of one of the types. */
562 else if (TYPE_PTR_TO_MEMBER_P (t1)
563 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
564 TYPE_PTRMEM_CLASS_TYPE (t2)))
566 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
567 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
569 if (DERIVED_FROM_P (class1, class2))
570 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
571 else if (DERIVED_FROM_P (class2, class1))
572 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
575 if (complain & tf_error)
576 error ("%s between distinct pointer-to-member types %qT and %qT "
577 "lacks a cast", location, t1, t2);
578 return error_mark_node;
582 return composite_pointer_type_r (t1, t2, location, complain);
585 /* Return the merged type of two types.
586 We assume that comptypes has already been done and returned 1;
587 if that isn't so, this may crash.
589 This just combines attributes and default arguments; any other
590 differences would cause the two types to compare unalike. */
593 merge_types (tree t1, tree t2)
595 enum tree_code code1;
596 enum tree_code code2;
599 /* Save time if the two types are the same. */
602 if (original_type (t1) == original_type (t2))
605 /* If one type is nonsense, use the other. */
606 if (t1 == error_mark_node)
608 if (t2 == error_mark_node)
611 /* Merge the attributes. */
612 attributes = (*targetm.merge_type_attributes) (t1, t2);
614 if (TYPE_PTRMEMFUNC_P (t1))
615 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
616 if (TYPE_PTRMEMFUNC_P (t2))
617 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
619 code1 = TREE_CODE (t1);
620 code2 = TREE_CODE (t2);
626 /* For two pointers, do this recursively on the target type. */
628 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
629 int quals = cp_type_quals (t1);
631 if (code1 == POINTER_TYPE)
632 t1 = build_pointer_type (target);
634 t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1));
635 t1 = build_type_attribute_variant (t1, attributes);
636 t1 = cp_build_qualified_type (t1, quals);
638 if (TREE_CODE (target) == METHOD_TYPE)
639 t1 = build_ptrmemfunc_type (t1);
648 quals = cp_type_quals (t1);
649 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
650 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
651 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
653 t1 = cp_build_qualified_type (t1, quals);
659 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
660 /* Save space: see if the result is identical to one of the args. */
661 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
662 return build_type_attribute_variant (t1, attributes);
663 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
664 return build_type_attribute_variant (t2, attributes);
665 /* Merge the element types, and have a size if either arg has one. */
666 t1 = build_cplus_array_type
667 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
672 /* Function types: prefer the one that specified arg types.
673 If both do, merge the arg types. Also merge the return types. */
675 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
676 tree p1 = TYPE_ARG_TYPES (t1);
677 tree p2 = TYPE_ARG_TYPES (t2);
680 /* Save space: see if the result is identical to one of the args. */
681 if (valtype == TREE_TYPE (t1) && ! p2)
682 return cp_build_type_attribute_variant (t1, attributes);
683 if (valtype == TREE_TYPE (t2) && ! p1)
684 return cp_build_type_attribute_variant (t2, attributes);
686 /* Simple way if one arg fails to specify argument types. */
687 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
689 rval = build_function_type (valtype, p2);
690 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
691 rval = build_exception_variant (rval, raises);
692 return cp_build_type_attribute_variant (rval, attributes);
694 raises = TYPE_RAISES_EXCEPTIONS (t1);
695 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
697 rval = build_function_type (valtype, p1);
699 rval = build_exception_variant (rval, raises);
700 return cp_build_type_attribute_variant (rval, attributes);
703 rval = build_function_type (valtype, commonparms (p1, p2));
704 t1 = build_exception_variant (rval, raises);
710 /* Get this value the long way, since TYPE_METHOD_BASETYPE
711 is just the main variant of this. */
712 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
713 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
716 /* If this was a member function type, get back to the
717 original type of type member function (i.e., without
718 the class instance variable up front. */
719 t1 = build_function_type (TREE_TYPE (t1),
720 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
721 t2 = build_function_type (TREE_TYPE (t2),
722 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
723 t3 = merge_types (t1, t2);
724 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
725 TYPE_ARG_TYPES (t3));
726 t1 = build_exception_variant (t3, raises);
731 /* There is no need to merge attributes into a TYPENAME_TYPE.
732 When the type is instantiated it will have whatever
733 attributes result from the instantiation. */
739 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
741 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
744 return cp_build_type_attribute_variant (t1, attributes);
747 /* Return the common type of two types.
748 We assume that comptypes has already been done and returned 1;
749 if that isn't so, this may crash.
751 This is the type for the result of most arithmetic operations
752 if the operands have the given two types. */
755 common_type (tree t1, tree t2)
757 enum tree_code code1;
758 enum tree_code code2;
760 /* If one type is nonsense, bail. */
761 if (t1 == error_mark_node || t2 == error_mark_node)
762 return error_mark_node;
764 code1 = TREE_CODE (t1);
765 code2 = TREE_CODE (t2);
767 if ((ARITHMETIC_TYPE_P (t1) || UNSCOPED_ENUM_P (t1)
768 || code1 == VECTOR_TYPE)
769 && (ARITHMETIC_TYPE_P (t2) || UNSCOPED_ENUM_P (t2)
770 || code2 == VECTOR_TYPE))
771 return type_after_usual_arithmetic_conversions (t1, t2);
773 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
774 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
775 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
776 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
777 "conversion", tf_warning_or_error);
782 /* Compare two exception specifier types for exactness or subsetness, if
783 allowed. Returns false for mismatch, true for match (same, or
786 [except.spec] "If a class X ... objects of class X or any class publicly
787 and unambiguously derived from X. Similarly, if a pointer type Y * ...
788 exceptions of type Y * or that are pointers to any type publicly and
789 unambiguously derived from Y. Otherwise a function only allows exceptions
790 that have the same type ..."
791 This does not mention cv qualifiers and is different to what throw
792 [except.throw] and catch [except.catch] will do. They will ignore the
793 top level cv qualifiers, and allow qualifiers in the pointer to class
796 We implement the letter of the standard. */
799 comp_except_types (tree a, tree b, bool exact)
801 if (same_type_p (a, b))
805 if (cp_type_quals (a) || cp_type_quals (b))
808 if (TREE_CODE (a) == POINTER_TYPE
809 && TREE_CODE (b) == POINTER_TYPE)
813 if (cp_type_quals (a) || cp_type_quals (b))
817 if (TREE_CODE (a) != RECORD_TYPE
818 || TREE_CODE (b) != RECORD_TYPE)
821 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
827 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
828 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
829 otherwise it must be exact. Exception lists are unordered, but
830 we've already filtered out duplicates. Most lists will be in order,
831 we should try to make use of that. */
834 comp_except_specs (const_tree t1, const_tree t2, bool exact)
843 if (t1 == NULL_TREE) /* T1 is ... */
844 return t2 == NULL_TREE || !exact;
845 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
846 return t2 != NULL_TREE && !TREE_VALUE (t2);
847 if (t2 == NULL_TREE) /* T2 is ... */
849 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
852 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
853 Count how many we find, to determine exactness. For exact matching and
854 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
856 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
858 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
860 tree a = TREE_VALUE (probe);
861 tree b = TREE_VALUE (t2);
863 if (comp_except_types (a, b, exact))
865 if (probe == base && exact)
866 base = TREE_CHAIN (probe);
871 if (probe == NULL_TREE)
874 return !exact || base == NULL_TREE || length == list_length (t1);
877 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
878 [] can match [size]. */
881 comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration)
890 /* The type of the array elements must be the same. */
891 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
894 d1 = TYPE_DOMAIN (t1);
895 d2 = TYPE_DOMAIN (t2);
900 /* If one of the arrays is dimensionless, and the other has a
901 dimension, they are of different types. However, it is valid to
909 declarations for an array object can specify
910 array types that differ by the presence or absence of a major
911 array bound (_dcl.array_). */
913 return allow_redeclaration;
915 /* Check that the dimensions are the same. */
917 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
919 max1 = TYPE_MAX_VALUE (d1);
920 max2 = TYPE_MAX_VALUE (d2);
921 if (processing_template_decl && !abi_version_at_least (2)
922 && !value_dependent_expression_p (max1)
923 && !value_dependent_expression_p (max2))
925 /* With abi-1 we do not fold non-dependent array bounds, (and
926 consequently mangle them incorrectly). We must therefore
927 fold them here, to verify the domains have the same
933 if (!cp_tree_equal (max1, max2))
939 /* Subroutine in comptypes. */
942 structural_comptypes (tree t1, tree t2, int strict)
947 /* Suppress errors caused by previously reported errors. */
948 if (t1 == error_mark_node || t2 == error_mark_node)
951 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
953 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
954 current instantiation. */
955 if (TREE_CODE (t1) == TYPENAME_TYPE)
956 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
959 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
961 if (TYPE_PTRMEMFUNC_P (t1))
962 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
963 if (TYPE_PTRMEMFUNC_P (t2))
964 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
966 /* Different classes of types can't be compatible. */
967 if (TREE_CODE (t1) != TREE_CODE (t2))
970 /* Qualifiers must match. For array types, we will check when we
971 recur on the array element types. */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
975 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
978 /* Allow for two different type nodes which have essentially the same
979 definition. Note that we already checked for equality of the type
980 qualifiers (just above). */
982 if (TREE_CODE (t1) != ARRAY_TYPE
983 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
986 /* Compare the types. Break out if they could be the same. */
987 switch (TREE_CODE (t1))
991 /* All void and bool types are the same. */
995 case FIXED_POINT_TYPE:
997 /* With these nodes, we can't determine type equivalence by
998 looking at what is stored in the nodes themselves, because
999 two nodes might have different TYPE_MAIN_VARIANTs but still
1000 represent the same type. For example, wchar_t and int could
1001 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
1002 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
1003 and are distinct types. On the other hand, int and the
1006 typedef int INT __attribute((may_alias));
1008 have identical properties, different TYPE_MAIN_VARIANTs, but
1009 represent the same type. The canonical type system keeps
1010 track of equivalence in this case, so we fall back on it. */
1011 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1013 case TEMPLATE_TEMPLATE_PARM:
1014 case BOUND_TEMPLATE_TEMPLATE_PARM:
1015 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1016 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1017 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1018 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1020 if (!comp_template_parms
1021 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1022 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1024 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1026 /* Don't check inheritance. */
1027 strict = COMPARE_STRICT;
1032 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1033 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1034 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1035 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1038 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1040 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1046 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1047 strict & ~COMPARE_REDECLARATION))
1049 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1053 case REFERENCE_TYPE:
1054 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1056 /* fall through to checks for pointer types */
1059 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1060 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1061 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1067 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1069 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1074 /* Target types must match incl. qualifiers. */
1075 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1079 case TEMPLATE_TYPE_PARM:
1080 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1081 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1082 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1083 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1088 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1089 TYPENAME_TYPE_FULLNAME (t2)))
1091 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1095 case UNBOUND_CLASS_TEMPLATE:
1096 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1098 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1103 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1108 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1109 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1113 case TYPE_PACK_EXPANSION:
1114 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1115 PACK_EXPANSION_PATTERN (t2));
1118 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1119 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1120 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1121 DECLTYPE_TYPE_EXPR (t2)))
1129 /* If we get here, we know that from a target independent POV the
1130 types are the same. Make sure the target attributes are also
1132 return targetm.comp_type_attributes (t1, t2);
1135 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1136 is a bitwise-or of the COMPARE_* flags. */
1139 comptypes (tree t1, tree t2, int strict)
1141 if (strict == COMPARE_STRICT)
1146 if (t1 == error_mark_node || t2 == error_mark_node)
1149 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1150 /* At least one of the types requires structural equality, so
1151 perform a deep check. */
1152 return structural_comptypes (t1, t2, strict);
1154 #ifdef ENABLE_CHECKING
1155 if (USE_CANONICAL_TYPES)
1157 bool result = structural_comptypes (t1, t2, strict);
1159 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1160 /* The two types are structurally equivalent, but their
1161 canonical types were different. This is a failure of the
1162 canonical type propagation code.*/
1164 ("canonical types differ for identical types %T and %T",
1166 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1167 /* Two types are structurally different, but the canonical
1168 types are the same. This means we were over-eager in
1169 assigning canonical types. */
1171 ("same canonical type node for different types %T and %T",
1177 if (USE_CANONICAL_TYPES)
1178 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1181 return structural_comptypes (t1, t2, strict);
1183 else if (strict == COMPARE_STRUCTURAL)
1184 return structural_comptypes (t1, t2, COMPARE_STRICT);
1186 return structural_comptypes (t1, t2, strict);
1189 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1192 at_least_as_qualified_p (const_tree type1, const_tree type2)
1194 int q1 = cp_type_quals (type1);
1195 int q2 = cp_type_quals (type2);
1197 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1198 return (q1 & q2) == q2;
1201 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1202 more cv-qualified that TYPE1, and 0 otherwise. */
1205 comp_cv_qualification (const_tree type1, const_tree type2)
1207 int q1 = cp_type_quals (type1);
1208 int q2 = cp_type_quals (type2);
1213 if ((q1 & q2) == q2)
1215 else if ((q1 & q2) == q1)
1221 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1222 subset of the cv-qualification signature of TYPE2, and the types
1223 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1226 comp_cv_qual_signature (tree type1, tree type2)
1228 if (comp_ptr_ttypes_real (type2, type1, -1))
1230 else if (comp_ptr_ttypes_real (type1, type2, -1))
1236 /* Subroutines of `comptypes'. */
1238 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1239 equivalent in the sense that functions with those parameter types
1240 can have equivalent types. The two lists must be equivalent,
1241 element by element. */
1244 compparms (const_tree parms1, const_tree parms2)
1248 /* An unspecified parmlist matches any specified parmlist
1249 whose argument types don't need default promotions. */
1251 for (t1 = parms1, t2 = parms2;
1253 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1255 /* If one parmlist is shorter than the other,
1256 they fail to match. */
1259 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1266 /* Process a sizeof or alignof expression where the operand is a
1270 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1275 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1276 if (type == error_mark_node)
1277 return error_mark_node;
1279 type = non_reference (type);
1280 if (TREE_CODE (type) == METHOD_TYPE)
1283 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
1284 "invalid application of %qs to a member function",
1285 operator_name_info[(int) op].name);
1286 value = size_one_node;
1289 dependent_p = dependent_type_p (type);
1291 complete_type (type);
1293 /* VLA types will have a non-constant size. In the body of an
1294 uninstantiated template, we don't need to try to compute the
1295 value, because the sizeof expression is not an integral
1296 constant expression in that case. And, if we do try to
1297 compute the value, we'll likely end up with SAVE_EXPRs, which
1298 the template substitution machinery does not expect to see. */
1299 || (processing_template_decl
1300 && COMPLETE_TYPE_P (type)
1301 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1303 value = build_min (op, size_type_node, type);
1304 TREE_READONLY (value) = 1;
1308 return c_sizeof_or_alignof_type (complete_type (type),
1313 /* Return the size of the type, without producing any warnings for
1314 types whose size cannot be taken. This routine should be used only
1315 in some other routine that has already produced a diagnostic about
1316 using the size of such a type. */
1318 cxx_sizeof_nowarn (tree type)
1320 if (TREE_CODE (type) == FUNCTION_TYPE
1321 || TREE_CODE (type) == VOID_TYPE
1322 || TREE_CODE (type) == ERROR_MARK)
1323 return size_one_node;
1324 else if (!COMPLETE_TYPE_P (type))
1325 return size_zero_node;
1327 return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false);
1330 /* Process a sizeof expression where the operand is an expression. */
1333 cxx_sizeof_expr (tree e, tsubst_flags_t complain)
1335 if (e == error_mark_node)
1336 return error_mark_node;
1338 if (processing_template_decl)
1340 e = build_min (SIZEOF_EXPR, size_type_node, e);
1341 TREE_SIDE_EFFECTS (e) = 0;
1342 TREE_READONLY (e) = 1;
1347 if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1351 if (complain & tf_error)
1352 error ("invalid application of %<sizeof%> to a bit-field");
1354 return error_mark_node;
1357 else if (is_overloaded_fn (e))
1359 if (complain & tf_error)
1360 permerror (input_location, "ISO C++ forbids applying %<sizeof%> to an expression of "
1363 return error_mark_node;
1366 else if (type_unknown_p (e))
1368 if (complain & tf_error)
1369 cxx_incomplete_type_error (e, TREE_TYPE (e));
1371 return error_mark_node;
1377 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error);
1380 /* Implement the __alignof keyword: Return the minimum required
1381 alignment of E, measured in bytes. For VAR_DECL's and
1382 FIELD_DECL's return DECL_ALIGN (which can be set from an
1383 "aligned" __attribute__ specification). */
1386 cxx_alignof_expr (tree e, tsubst_flags_t complain)
1390 if (e == error_mark_node)
1391 return error_mark_node;
1393 if (processing_template_decl)
1395 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1396 TREE_SIDE_EFFECTS (e) = 0;
1397 TREE_READONLY (e) = 1;
1402 if (TREE_CODE (e) == VAR_DECL)
1403 t = size_int (DECL_ALIGN_UNIT (e));
1404 else if (TREE_CODE (e) == COMPONENT_REF
1405 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1406 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1408 if (complain & tf_error)
1409 error ("invalid application of %<__alignof%> to a bit-field");
1411 return error_mark_node;
1414 else if (TREE_CODE (e) == COMPONENT_REF
1415 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1416 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1417 else if (is_overloaded_fn (e))
1419 if (complain & tf_error)
1420 permerror (input_location, "ISO C++ forbids applying %<__alignof%> to an expression of "
1423 return error_mark_node;
1424 if (TREE_CODE (e) == FUNCTION_DECL)
1425 t = size_int (DECL_ALIGN_UNIT (e));
1429 else if (type_unknown_p (e))
1431 if (complain & tf_error)
1432 cxx_incomplete_type_error (e, TREE_TYPE (e));
1434 return error_mark_node;
1438 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR,
1439 complain & tf_error);
1441 return fold_convert (size_type_node, t);
1444 /* Process a sizeof or alignof expression E with code OP where the operand
1445 is an expression. */
1448 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain)
1450 if (op == SIZEOF_EXPR)
1451 return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none);
1453 return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none);
1456 /* EXPR is being used in a context that is not a function call.
1461 The expression can be used only as the left-hand operand of a
1462 member function call.
1464 [expr.mptr.operator]
1466 If the result of .* or ->* is a function, then that result can be
1467 used only as the operand for the function call operator ().
1469 by issuing an error message if appropriate. Returns true iff EXPR
1470 violates these rules. */
1473 invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain)
1475 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1477 if (complain & tf_error)
1478 error ("invalid use of non-static member function");
1484 /* If EXP is a reference to a bitfield, and the type of EXP does not
1485 match the declared type of the bitfield, return the declared type
1486 of the bitfield. Otherwise, return NULL_TREE. */
1489 is_bitfield_expr_with_lowered_type (const_tree exp)
1491 switch (TREE_CODE (exp))
1494 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1495 ? TREE_OPERAND (exp, 1)
1496 : TREE_OPERAND (exp, 0)))
1498 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1501 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1505 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1511 field = TREE_OPERAND (exp, 1);
1512 if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field))
1514 if (same_type_ignoring_top_level_qualifiers_p
1515 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1517 return DECL_BIT_FIELD_TYPE (field);
1521 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1522 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1523 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1531 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1532 bitfield with a lowered type, the type of EXP is returned, rather
1536 unlowered_expr_type (const_tree exp)
1540 type = is_bitfield_expr_with_lowered_type (exp);
1542 type = TREE_TYPE (exp);
1547 /* Perform the conversions in [expr] that apply when an lvalue appears
1548 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1549 function-to-pointer conversions. In addition, manifest constants
1550 are replaced by their values, and bitfield references are converted
1551 to their declared types.
1553 Although the returned value is being used as an rvalue, this
1554 function does not wrap the returned expression in a
1555 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1556 that the return value is no longer an lvalue. */
1559 decay_conversion (tree exp)
1562 enum tree_code code;
1564 type = TREE_TYPE (exp);
1565 if (type == error_mark_node)
1566 return error_mark_node;
1568 if (type_unknown_p (exp))
1570 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1571 return error_mark_node;
1574 exp = decl_constant_value (exp);
1575 if (error_operand_p (exp))
1576 return error_mark_node;
1578 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1579 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1580 code = TREE_CODE (type);
1581 if (code == VOID_TYPE)
1583 error ("void value not ignored as it ought to be");
1584 return error_mark_node;
1586 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error))
1587 return error_mark_node;
1588 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1589 return cp_build_unary_op (ADDR_EXPR, exp, 0, tf_warning_or_error);
1590 if (code == ARRAY_TYPE)
1595 if (TREE_CODE (exp) == INDIRECT_REF)
1596 return build_nop (build_pointer_type (TREE_TYPE (type)),
1597 TREE_OPERAND (exp, 0));
1599 if (TREE_CODE (exp) == COMPOUND_EXPR)
1601 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1602 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1603 TREE_OPERAND (exp, 0), op1);
1607 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1609 error ("invalid use of non-lvalue array");
1610 return error_mark_node;
1613 ptrtype = build_pointer_type (TREE_TYPE (type));
1615 if (TREE_CODE (exp) == VAR_DECL)
1617 if (!cxx_mark_addressable (exp))
1618 return error_mark_node;
1619 adr = build_nop (ptrtype, build_address (exp));
1622 /* This way is better for a COMPONENT_REF since it can
1623 simplify the offset for a component. */
1624 adr = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error);
1625 return cp_convert (ptrtype, adr);
1628 /* If a bitfield is used in a context where integral promotion
1629 applies, then the caller is expected to have used
1630 default_conversion. That function promotes bitfields correctly
1631 before calling this function. At this point, if we have a
1632 bitfield referenced, we may assume that is not subject to
1633 promotion, and that, therefore, the type of the resulting rvalue
1634 is the declared type of the bitfield. */
1635 exp = convert_bitfield_to_declared_type (exp);
1637 /* We do not call rvalue() here because we do not want to wrap EXP
1638 in a NON_LVALUE_EXPR. */
1642 Non-class rvalues always have cv-unqualified types. */
1643 type = TREE_TYPE (exp);
1644 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1645 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1650 /* Perform preparatory conversions, as part of the "usual arithmetic
1651 conversions". In particular, as per [expr]:
1653 Whenever an lvalue expression appears as an operand of an
1654 operator that expects the rvalue for that operand, the
1655 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1656 standard conversions are applied to convert the expression to an
1659 In addition, we perform integral promotions here, as those are
1660 applied to both operands to a binary operator before determining
1661 what additional conversions should apply. */
1664 default_conversion (tree exp)
1666 /* Perform the integral promotions first so that bitfield
1667 expressions (which may promote to "int", even if the bitfield is
1668 declared "unsigned") are promoted correctly. */
1669 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1670 exp = perform_integral_promotions (exp);
1671 /* Perform the other conversions. */
1672 exp = decay_conversion (exp);
1677 /* EXPR is an expression with an integral or enumeration type.
1678 Perform the integral promotions in [conv.prom], and return the
1682 perform_integral_promotions (tree expr)
1689 If the bitfield has an enumerated type, it is treated as any
1690 other value of that type for promotion purposes. */
1691 type = is_bitfield_expr_with_lowered_type (expr);
1692 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1693 type = TREE_TYPE (expr);
1694 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1695 promoted_type = type_promotes_to (type);
1696 if (type != promoted_type)
1697 expr = cp_convert (promoted_type, expr);
1701 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1702 decay_conversion to one. */
1705 string_conv_p (const_tree totype, const_tree exp, int warn)
1709 if (TREE_CODE (totype) != POINTER_TYPE)
1712 t = TREE_TYPE (totype);
1713 if (!same_type_p (t, char_type_node)
1714 && !same_type_p (t, char16_type_node)
1715 && !same_type_p (t, char32_type_node)
1716 && !same_type_p (t, wchar_type_node))
1719 if (TREE_CODE (exp) == STRING_CST)
1721 /* Make sure that we don't try to convert between char and wide chars. */
1722 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1727 /* Is this a string constant which has decayed to 'const char *'? */
1728 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1729 if (!same_type_p (TREE_TYPE (exp), t))
1732 if (TREE_CODE (exp) != ADDR_EXPR
1733 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1737 /* This warning is not very useful, as it complains about printf. */
1739 warning (OPT_Wwrite_strings,
1740 "deprecated conversion from string constant to %qT",
1746 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1747 can, for example, use as an lvalue. This code used to be in
1748 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1749 expressions, where we're dealing with aggregates. But now it's again only
1750 called from unary_complex_lvalue. The case (in particular) that led to
1751 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1755 rationalize_conditional_expr (enum tree_code code, tree t,
1756 tsubst_flags_t complain)
1758 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1759 the first operand is always the one to be used if both operands
1760 are equal, so we know what conditional expression this used to be. */
1761 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1763 tree op0 = TREE_OPERAND (t, 0);
1764 tree op1 = TREE_OPERAND (t, 1);
1766 /* The following code is incorrect if either operand side-effects. */
1767 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1768 && !TREE_SIDE_EFFECTS (op1));
1770 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1771 ? LE_EXPR : GE_EXPR),
1772 op0, TREE_CODE (op0),
1773 op1, TREE_CODE (op1),
1774 /*overloaded_p=*/NULL,
1776 cp_build_unary_op (code, op0, 0, complain),
1777 cp_build_unary_op (code, op1, 0, complain),
1782 build_conditional_expr (TREE_OPERAND (t, 0),
1783 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0,
1785 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0,
1790 /* Given the TYPE of an anonymous union field inside T, return the
1791 FIELD_DECL for the field. If not found return NULL_TREE. Because
1792 anonymous unions can nest, we must also search all anonymous unions
1793 that are directly reachable. */
1796 lookup_anon_field (tree t, tree type)
1800 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1802 if (TREE_STATIC (field))
1804 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1807 /* If we find it directly, return the field. */
1808 if (DECL_NAME (field) == NULL_TREE
1809 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1814 /* Otherwise, it could be nested, search harder. */
1815 if (DECL_NAME (field) == NULL_TREE
1816 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1818 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1826 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1827 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1828 non-NULL, it indicates the path to the base used to name MEMBER.
1829 If PRESERVE_REFERENCE is true, the expression returned will have
1830 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1831 returned will have the type referred to by the reference.
1833 This function does not perform access control; that is either done
1834 earlier by the parser when the name of MEMBER is resolved to MEMBER
1835 itself, or later when overload resolution selects one of the
1836 functions indicated by MEMBER. */
1839 build_class_member_access_expr (tree object, tree member,
1840 tree access_path, bool preserve_reference,
1841 tsubst_flags_t complain)
1845 tree result = NULL_TREE;
1847 if (error_operand_p (object) || error_operand_p (member))
1848 return error_mark_node;
1850 gcc_assert (DECL_P (member) || BASELINK_P (member));
1854 The type of the first expression shall be "class object" (of a
1856 object_type = TREE_TYPE (object);
1857 if (!currently_open_class (object_type)
1858 && !complete_type_or_else (object_type, object))
1859 return error_mark_node;
1860 if (!CLASS_TYPE_P (object_type))
1862 if (complain & tf_error)
1863 error ("request for member %qD in %qE, which is of non-class type %qT",
1864 member, object, object_type);
1865 return error_mark_node;
1868 /* The standard does not seem to actually say that MEMBER must be a
1869 member of OBJECT_TYPE. However, that is clearly what is
1871 if (DECL_P (member))
1873 member_scope = DECL_CLASS_CONTEXT (member);
1875 if (TREE_DEPRECATED (member))
1876 warn_deprecated_use (member);
1879 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1880 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1881 presently be the anonymous union. Go outwards until we find a
1882 type related to OBJECT_TYPE. */
1883 while (ANON_AGGR_TYPE_P (member_scope)
1884 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1886 member_scope = TYPE_CONTEXT (member_scope);
1887 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1889 if (complain & tf_error)
1891 if (TREE_CODE (member) == FIELD_DECL)
1892 error ("invalid use of nonstatic data member %qE", member);
1894 error ("%qD is not a member of %qT", member, object_type);
1896 return error_mark_node;
1899 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1900 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1901 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1903 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1905 object = cp_build_indirect_ref (temp, NULL, complain);
1908 /* In [expr.ref], there is an explicit list of the valid choices for
1909 MEMBER. We check for each of those cases here. */
1910 if (TREE_CODE (member) == VAR_DECL)
1912 /* A static data member. */
1914 /* If OBJECT has side-effects, they are supposed to occur. */
1915 if (TREE_SIDE_EFFECTS (object))
1916 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1918 else if (TREE_CODE (member) == FIELD_DECL)
1920 /* A non-static data member. */
1925 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1926 && integer_zerop (TREE_OPERAND (object, 0)));
1928 /* Convert OBJECT to the type of MEMBER. */
1929 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1930 TYPE_MAIN_VARIANT (member_scope)))
1935 binfo = lookup_base (access_path ? access_path : object_type,
1936 member_scope, ba_unique, &kind);
1937 if (binfo == error_mark_node)
1938 return error_mark_node;
1940 /* It is invalid to try to get to a virtual base of a
1941 NULL object. The most common cause is invalid use of
1943 if (null_object_p && kind == bk_via_virtual)
1945 if (complain & tf_error)
1947 error ("invalid access to non-static data member %qD of "
1950 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1952 return error_mark_node;
1955 /* Convert to the base. */
1956 object = build_base_path (PLUS_EXPR, object, binfo,
1958 /* If we found the base successfully then we should be able
1959 to convert to it successfully. */
1960 gcc_assert (object != error_mark_node);
1963 /* Complain about other invalid uses of offsetof, even though they will
1964 give the right answer. Note that we complain whether or not they
1965 actually used the offsetof macro, since there's no way to know at this
1966 point. So we just give a warning, instead of a pedwarn. */
1967 /* Do not produce this warning for base class field references, because
1968 we know for a fact that didn't come from offsetof. This does occur
1969 in various testsuite cases where a null object is passed where a
1970 vtable access is required. */
1971 if (null_object_p && warn_invalid_offsetof
1972 && CLASSTYPE_NON_POD_P (object_type)
1973 && !DECL_FIELD_IS_BASE (member)
1975 && (complain & tf_warning))
1977 warning (OPT_Winvalid_offsetof,
1978 "invalid access to non-static data member %qD "
1979 " of NULL object", member);
1980 warning (OPT_Winvalid_offsetof,
1981 "(perhaps the %<offsetof%> macro was used incorrectly)");
1984 /* If MEMBER is from an anonymous aggregate, we have converted
1985 OBJECT so that it refers to the class containing the
1986 anonymous union. Generate a reference to the anonymous union
1987 itself, and recur to find MEMBER. */
1988 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1989 /* When this code is called from build_field_call, the
1990 object already has the type of the anonymous union.
1991 That is because the COMPONENT_REF was already
1992 constructed, and was then disassembled before calling
1993 build_field_call. After the function-call code is
1994 cleaned up, this waste can be eliminated. */
1995 && (!same_type_ignoring_top_level_qualifiers_p
1996 (TREE_TYPE (object), DECL_CONTEXT (member))))
1998 tree anonymous_union;
2000 anonymous_union = lookup_anon_field (TREE_TYPE (object),
2001 DECL_CONTEXT (member));
2002 object = build_class_member_access_expr (object,
2004 /*access_path=*/NULL_TREE,
2009 /* Compute the type of the field, as described in [expr.ref]. */
2010 type_quals = TYPE_UNQUALIFIED;
2011 member_type = TREE_TYPE (member);
2012 if (TREE_CODE (member_type) != REFERENCE_TYPE)
2014 type_quals = (cp_type_quals (member_type)
2015 | cp_type_quals (object_type));
2017 /* A field is const (volatile) if the enclosing object, or the
2018 field itself, is const (volatile). But, a mutable field is
2019 not const, even within a const object. */
2020 if (DECL_MUTABLE_P (member))
2021 type_quals &= ~TYPE_QUAL_CONST;
2022 member_type = cp_build_qualified_type (member_type, type_quals);
2025 result = build3 (COMPONENT_REF, member_type, object, member,
2027 result = fold_if_not_in_template (result);
2029 /* Mark the expression const or volatile, as appropriate. Even
2030 though we've dealt with the type above, we still have to mark the
2031 expression itself. */
2032 if (type_quals & TYPE_QUAL_CONST)
2033 TREE_READONLY (result) = 1;
2034 if (type_quals & TYPE_QUAL_VOLATILE)
2035 TREE_THIS_VOLATILE (result) = 1;
2037 else if (BASELINK_P (member))
2039 /* The member is a (possibly overloaded) member function. */
2043 /* If the MEMBER is exactly one static member function, then we
2044 know the type of the expression. Otherwise, we must wait
2045 until overload resolution has been performed. */
2046 functions = BASELINK_FUNCTIONS (member);
2047 if (TREE_CODE (functions) == FUNCTION_DECL
2048 && DECL_STATIC_FUNCTION_P (functions))
2049 type = TREE_TYPE (functions);
2051 type = unknown_type_node;
2052 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2053 base. That will happen when the function is called. */
2054 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2056 else if (TREE_CODE (member) == CONST_DECL)
2058 /* The member is an enumerator. */
2060 /* If OBJECT has side-effects, they are supposed to occur. */
2061 if (TREE_SIDE_EFFECTS (object))
2062 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2067 if (complain & tf_error)
2068 error ("invalid use of %qD", member);
2069 return error_mark_node;
2072 if (!preserve_reference)
2075 If E2 is declared to have type "reference to T", then ... the
2076 type of E1.E2 is T. */
2077 result = convert_from_reference (result);
2082 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2083 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2086 lookup_destructor (tree object, tree scope, tree dtor_name)
2088 tree object_type = TREE_TYPE (object);
2089 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2092 if (scope && !check_dtor_name (scope, dtor_type))
2094 error ("qualified type %qT does not match destructor name ~%qT",
2096 return error_mark_node;
2098 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2100 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2101 TYPE_MAIN_VARIANT (object_type), dtor_type);
2102 return error_mark_node;
2104 expr = lookup_member (dtor_type, complete_dtor_identifier,
2105 /*protect=*/1, /*want_type=*/false);
2106 expr = (adjust_result_of_qualified_name_lookup
2107 (expr, dtor_type, object_type));
2111 /* An expression of the form "A::template B" has been resolved to
2112 DECL. Issue a diagnostic if B is not a template or template
2116 check_template_keyword (tree decl)
2118 /* The standard says:
2122 If a name prefixed by the keyword template is not a member
2123 template, the program is ill-formed.
2125 DR 228 removed the restriction that the template be a member
2128 DR 96, if accepted would add the further restriction that explicit
2129 template arguments must be provided if the template keyword is
2130 used, but, as of 2005-10-16, that DR is still in "drafting". If
2131 this DR is accepted, then the semantic checks here can be
2132 simplified, as the entity named must in fact be a template
2133 specialization, rather than, as at present, a set of overloaded
2134 functions containing at least one template function. */
2135 if (TREE_CODE (decl) != TEMPLATE_DECL
2136 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2138 if (!is_overloaded_fn (decl))
2139 permerror (input_location, "%qD is not a template", decl);
2144 if (BASELINK_P (fns))
2145 fns = BASELINK_FUNCTIONS (fns);
2148 tree fn = OVL_CURRENT (fns);
2149 if (TREE_CODE (fn) == TEMPLATE_DECL
2150 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2152 if (TREE_CODE (fn) == FUNCTION_DECL
2153 && DECL_USE_TEMPLATE (fn)
2154 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2156 fns = OVL_NEXT (fns);
2159 permerror (input_location, "%qD is not a template", decl);
2164 /* This function is called by the parser to process a class member
2165 access expression of the form OBJECT.NAME. NAME is a node used by
2166 the parser to represent a name; it is not yet a DECL. It may,
2167 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2168 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2169 there is no reason to do the lookup twice, so the parser keeps the
2170 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2171 be a template via the use of the "A::template B" syntax. */
2174 finish_class_member_access_expr (tree object, tree name, bool template_p,
2175 tsubst_flags_t complain)
2180 tree access_path = NULL_TREE;
2181 tree orig_object = object;
2182 tree orig_name = name;
2184 if (object == error_mark_node || name == error_mark_node)
2185 return error_mark_node;
2187 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2188 if (!objc_is_public (object, name))
2189 return error_mark_node;
2191 object_type = TREE_TYPE (object);
2193 if (processing_template_decl)
2195 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2196 dependent_type_p (object_type)
2197 /* If NAME is just an IDENTIFIER_NODE, then the expression
2199 || TREE_CODE (object) == IDENTIFIER_NODE
2200 /* If NAME is "f<args>", where either 'f' or 'args' is
2201 dependent, then the expression is dependent. */
2202 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2203 && dependent_template_id_p (TREE_OPERAND (name, 0),
2204 TREE_OPERAND (name, 1)))
2205 /* If NAME is "T::X" where "T" is dependent, then the
2206 expression is dependent. */
2207 || (TREE_CODE (name) == SCOPE_REF
2208 && TYPE_P (TREE_OPERAND (name, 0))
2209 && dependent_type_p (TREE_OPERAND (name, 0))))
2210 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2211 object = build_non_dependent_expr (object);
2216 The type of the first expression shall be "class object" (of a
2218 if (!currently_open_class (object_type)
2219 && !complete_type_or_else (object_type, object))
2220 return error_mark_node;
2221 if (!CLASS_TYPE_P (object_type))
2223 if (complain & tf_error)
2224 error ("request for member %qD in %qE, which is of non-class type %qT",
2225 name, object, object_type);
2226 return error_mark_node;
2229 if (BASELINK_P (name))
2230 /* A member function that has already been looked up. */
2234 bool is_template_id = false;
2235 tree template_args = NULL_TREE;
2238 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2240 is_template_id = true;
2241 template_args = TREE_OPERAND (name, 1);
2242 name = TREE_OPERAND (name, 0);
2244 if (TREE_CODE (name) == OVERLOAD)
2245 name = DECL_NAME (get_first_fn (name));
2246 else if (DECL_P (name))
2247 name = DECL_NAME (name);
2250 if (TREE_CODE (name) == SCOPE_REF)
2252 /* A qualified name. The qualifying class or namespace `S'
2253 has already been looked up; it is either a TYPE or a
2255 scope = TREE_OPERAND (name, 0);
2256 name = TREE_OPERAND (name, 1);
2258 /* If SCOPE is a namespace, then the qualified name does not
2259 name a member of OBJECT_TYPE. */
2260 if (TREE_CODE (scope) == NAMESPACE_DECL)
2262 if (complain & tf_error)
2263 error ("%<%D::%D%> is not a member of %qT",
2264 scope, name, object_type);
2265 return error_mark_node;
2268 gcc_assert (CLASS_TYPE_P (scope));
2269 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2270 || TREE_CODE (name) == BIT_NOT_EXPR);
2272 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2273 access_path = lookup_base (object_type, scope, ba_check, NULL);
2274 if (access_path == error_mark_node)
2275 return error_mark_node;
2278 if (complain & tf_error)
2279 error ("%qT is not a base of %qT", scope, object_type);
2280 return error_mark_node;
2286 access_path = object_type;
2289 if (TREE_CODE (name) == BIT_NOT_EXPR)
2290 member = lookup_destructor (object, scope, name);
2293 /* Look up the member. */
2294 member = lookup_member (access_path, name, /*protect=*/1,
2295 /*want_type=*/false);
2296 if (member == NULL_TREE)
2298 if (complain & tf_error)
2299 error ("%qD has no member named %qE", object_type, name);
2300 return error_mark_node;
2302 if (member == error_mark_node)
2303 return error_mark_node;
2308 tree templ = member;
2310 if (BASELINK_P (templ))
2311 templ = lookup_template_function (templ, template_args);
2314 if (complain & tf_error)
2315 error ("%qD is not a member template function", name);
2316 return error_mark_node;
2321 if (TREE_DEPRECATED (member))
2322 warn_deprecated_use (member);
2325 check_template_keyword (member);
2327 expr = build_class_member_access_expr (object, member, access_path,
2328 /*preserve_reference=*/false,
2330 if (processing_template_decl && expr != error_mark_node)
2332 if (BASELINK_P (member))
2334 if (TREE_CODE (orig_name) == SCOPE_REF)
2335 BASELINK_QUALIFIED_P (member) = 1;
2338 return build_min_non_dep (COMPONENT_REF, expr,
2339 orig_object, orig_name,
2346 /* Return an expression for the MEMBER_NAME field in the internal
2347 representation of PTRMEM, a pointer-to-member function. (Each
2348 pointer-to-member function type gets its own RECORD_TYPE so it is
2349 more convenient to access the fields by name than by FIELD_DECL.)
2350 This routine converts the NAME to a FIELD_DECL and then creates the
2351 node for the complete expression. */
2354 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2360 /* This code is a stripped down version of
2361 build_class_member_access_expr. It does not work to use that
2362 routine directly because it expects the object to be of class
2364 ptrmem_type = TREE_TYPE (ptrmem);
2365 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2366 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2367 /*want_type=*/false);
2368 member_type = cp_build_qualified_type (TREE_TYPE (member),
2369 cp_type_quals (ptrmem_type));
2370 return fold_build3 (COMPONENT_REF, member_type,
2371 ptrmem, member, NULL_TREE);
2374 /* Given an expression PTR for a pointer, return an expression
2375 for the value pointed to.
2376 ERRORSTRING is the name of the operator to appear in error messages.
2378 This function may need to overload OPERATOR_FNNAME.
2379 Must also handle REFERENCE_TYPEs for C++. */
2382 build_x_indirect_ref (tree expr, const char *errorstring,
2383 tsubst_flags_t complain)
2385 tree orig_expr = expr;
2388 if (processing_template_decl)
2390 if (type_dependent_expression_p (expr))
2391 return build_min_nt (INDIRECT_REF, expr);
2392 expr = build_non_dependent_expr (expr);
2395 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2396 NULL_TREE, /*overloaded_p=*/NULL, complain);
2398 rval = cp_build_indirect_ref (expr, errorstring, complain);
2400 if (processing_template_decl && rval != error_mark_node)
2401 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2406 /* Helper function called from c-common. */
2408 build_indirect_ref (tree ptr, const char *errorstring,
2409 location_t loc __attribute__ ((__unused__)))
2411 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error);
2415 cp_build_indirect_ref (tree ptr, const char *errorstring,
2416 tsubst_flags_t complain)
2420 if (ptr == error_mark_node)
2421 return error_mark_node;
2423 if (ptr == current_class_ptr)
2424 return current_class_ref;
2426 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2427 ? ptr : decay_conversion (ptr));
2428 type = TREE_TYPE (pointer);
2430 if (POINTER_TYPE_P (type))
2434 If the type of the expression is "pointer to T," the type
2435 of the result is "T."
2437 We must use the canonical variant because certain parts of
2438 the back end, like fold, do pointer comparisons between
2440 tree t = canonical_type_variant (TREE_TYPE (type));
2442 if (CONVERT_EXPR_P (ptr)
2443 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2445 /* If a warning is issued, mark it to avoid duplicates from
2446 the backend. This only needs to be done at
2447 warn_strict_aliasing > 2. */
2448 if (warn_strict_aliasing > 2)
2449 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2450 type, TREE_OPERAND (ptr, 0)))
2451 TREE_NO_WARNING (ptr) = 1;
2454 if (VOID_TYPE_P (t))
2456 /* A pointer to incomplete type (other than cv void) can be
2457 dereferenced [expr.unary.op]/1 */
2458 if (complain & tf_error)
2459 error ("%qT is not a pointer-to-object type", type);
2460 return error_mark_node;
2462 else if (TREE_CODE (pointer) == ADDR_EXPR
2463 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2464 /* The POINTER was something like `&x'. We simplify `*&x' to
2466 return TREE_OPERAND (pointer, 0);
2469 tree ref = build1 (INDIRECT_REF, t, pointer);
2471 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2472 so that we get the proper error message if the result is used
2473 to assign to. Also, &* is supposed to be a no-op. */
2474 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2475 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2476 TREE_SIDE_EFFECTS (ref)
2477 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2481 else if (!(complain & tf_error))
2482 /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */
2484 /* `pointer' won't be an error_mark_node if we were given a
2485 pointer to member, so it's cool to check for this here. */
2486 else if (TYPE_PTR_TO_MEMBER_P (type))
2487 error ("invalid use of %qs on pointer to member", errorstring);
2488 else if (pointer != error_mark_node)
2491 error ("invalid type argument of %qs", errorstring);
2493 error ("invalid type argument");
2495 return error_mark_node;
2498 /* This handles expressions of the form "a[i]", which denotes
2501 This is logically equivalent in C to *(a+i), but we may do it differently.
2502 If A is a variable or a member, we generate a primitive ARRAY_REF.
2503 This avoids forcing the array out of registers, and can work on
2504 arrays that are not lvalues (for example, members of structures returned
2507 If INDEX is of some user-defined type, it must be converted to
2508 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2509 will inherit the type of the array, which will be some pointer type.
2511 LOC is the location to use in building the array reference. */
2514 build_array_ref (tree array, tree idx, location_t loc)
2520 error_at (loc, "subscript missing in array reference");
2521 return error_mark_node;
2524 if (TREE_TYPE (array) == error_mark_node
2525 || TREE_TYPE (idx) == error_mark_node)
2526 return error_mark_node;
2528 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2530 switch (TREE_CODE (array))
2534 tree value = build_array_ref (TREE_OPERAND (array, 1), idx, loc);
2535 ret = build2 (COMPOUND_EXPR, TREE_TYPE (value),
2536 TREE_OPERAND (array, 0), value);
2537 SET_EXPR_LOCATION (ret, loc);
2542 ret = build_conditional_expr
2543 (TREE_OPERAND (array, 0),
2544 build_array_ref (TREE_OPERAND (array, 1), idx, loc),
2545 build_array_ref (TREE_OPERAND (array, 2), idx, loc),
2546 tf_warning_or_error);
2547 SET_EXPR_LOCATION (ret, loc);
2554 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2558 warn_array_subscript_with_type_char (idx);
2560 if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2562 error_at (loc, "array subscript is not an integer");
2563 return error_mark_node;
2566 /* Apply integral promotions *after* noticing character types.
2567 (It is unclear why we do these promotions -- the standard
2568 does not say that we should. In fact, the natural thing would
2569 seem to be to convert IDX to ptrdiff_t; we're performing
2570 pointer arithmetic.) */
2571 idx = perform_integral_promotions (idx);
2573 /* An array that is indexed by a non-constant
2574 cannot be stored in a register; we must be able to do
2575 address arithmetic on its address.
2576 Likewise an array of elements of variable size. */
2577 if (TREE_CODE (idx) != INTEGER_CST
2578 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2579 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2582 if (!cxx_mark_addressable (array))
2583 return error_mark_node;
2586 /* An array that is indexed by a constant value which is not within
2587 the array bounds cannot be stored in a register either; because we
2588 would get a crash in store_bit_field/extract_bit_field when trying
2589 to access a non-existent part of the register. */
2590 if (TREE_CODE (idx) == INTEGER_CST
2591 && TYPE_DOMAIN (TREE_TYPE (array))
2592 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2594 if (!cxx_mark_addressable (array))
2595 return error_mark_node;
2598 if (!lvalue_p (array))
2599 pedwarn (loc, OPT_pedantic,
2600 "ISO C++ forbids subscripting non-lvalue array");
2602 /* Note in C++ it is valid to subscript a `register' array, since
2603 it is valid to take the address of something with that
2604 storage specification. */
2608 while (TREE_CODE (foo) == COMPONENT_REF)
2609 foo = TREE_OPERAND (foo, 0);
2610 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2611 warning_at (loc, OPT_Wextra,
2612 "subscripting array declared %<register%>");
2615 type = TREE_TYPE (TREE_TYPE (array));
2616 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2617 /* Array ref is const/volatile if the array elements are
2618 or if the array is.. */
2619 TREE_READONLY (rval)
2620 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2621 TREE_SIDE_EFFECTS (rval)
2622 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2623 TREE_THIS_VOLATILE (rval)
2624 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2625 ret = require_complete_type (fold_if_not_in_template (rval));
2626 SET_EXPR_LOCATION (ret, loc);
2631 tree ar = default_conversion (array);
2632 tree ind = default_conversion (idx);
2634 /* Put the integer in IND to simplify error checking. */
2635 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2642 if (ar == error_mark_node)
2645 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2647 error_at (loc, "subscripted value is neither array nor pointer");
2648 return error_mark_node;
2650 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2652 error_at (loc, "array subscript is not an integer");
2653 return error_mark_node;
2656 warn_array_subscript_with_type_char (idx);
2658 ret = cp_build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind,
2659 tf_warning_or_error),
2661 tf_warning_or_error);
2662 protected_set_expr_location (ret, loc);
2667 /* Resolve a pointer to member function. INSTANCE is the object
2668 instance to use, if the member points to a virtual member.
2670 This used to avoid checking for virtual functions if basetype
2671 has no virtual functions, according to an earlier ANSI draft.
2672 With the final ISO C++ rules, such an optimization is
2673 incorrect: A pointer to a derived member can be static_cast
2674 to pointer-to-base-member, as long as the dynamic object
2675 later has the right member. */
2678 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2680 if (TREE_CODE (function) == OFFSET_REF)
2681 function = TREE_OPERAND (function, 1);
2683 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2685 tree idx, delta, e1, e2, e3, vtbl, basetype;
2686 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2688 tree instance_ptr = *instance_ptrptr;
2689 tree instance_save_expr = 0;
2690 if (instance_ptr == error_mark_node)
2692 if (TREE_CODE (function) == PTRMEM_CST)
2694 /* Extracting the function address from a pmf is only
2695 allowed with -Wno-pmf-conversions. It only works for
2697 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2698 e1 = convert (fntype, e1);
2703 error ("object missing in use of %qE", function);
2704 return error_mark_node;
2708 if (TREE_SIDE_EFFECTS (instance_ptr))
2709 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2711 if (TREE_SIDE_EFFECTS (function))
2712 function = save_expr (function);
2714 /* Start by extracting all the information from the PMF itself. */
2715 e3 = pfn_from_ptrmemfunc (function);
2716 delta = delta_from_ptrmemfunc (function);
2717 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2718 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2720 case ptrmemfunc_vbit_in_pfn:
2721 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node,
2722 tf_warning_or_error);
2723 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node,
2724 tf_warning_or_error);
2727 case ptrmemfunc_vbit_in_delta:
2728 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node,
2729 tf_warning_or_error);
2730 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node,
2731 tf_warning_or_error);
2738 /* Convert down to the right base before using the instance. A
2739 special case is that in a pointer to member of class C, C may
2740 be incomplete. In that case, the function will of course be
2741 a member of C, and no conversion is required. In fact,
2742 lookup_base will fail in that case, because incomplete
2743 classes do not have BINFOs. */
2744 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2745 if (!same_type_ignoring_top_level_qualifiers_p
2746 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2748 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2749 basetype, ba_check, NULL);
2750 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2752 if (instance_ptr == error_mark_node)
2753 return error_mark_node;
2755 /* ...and then the delta in the PMF. */
2756 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2757 instance_ptr, fold_convert (sizetype, delta));
2759 /* Hand back the adjusted 'this' argument to our caller. */
2760 *instance_ptrptr = instance_ptr;
2762 /* Next extract the vtable pointer from the object. */
2763 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2765 vtbl = cp_build_indirect_ref (vtbl, NULL, tf_warning_or_error);
2767 /* Finally, extract the function pointer from the vtable. */
2768 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2769 fold_convert (sizetype, idx));
2770 e2 = cp_build_indirect_ref (e2, NULL, tf_warning_or_error);
2771 TREE_CONSTANT (e2) = 1;
2773 /* When using function descriptors, the address of the
2774 vtable entry is treated as a function pointer. */
2775 if (TARGET_VTABLE_USES_DESCRIPTORS)
2776 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2777 cp_build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1,
2778 tf_warning_or_error));
2780 e2 = fold_convert (TREE_TYPE (e3), e2);
2781 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error);
2783 /* Make sure this doesn't get evaluated first inside one of the
2784 branches of the COND_EXPR. */
2785 if (instance_save_expr)
2786 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2787 instance_save_expr, e1);
2794 /* Used by the C-common bits. */
2796 build_function_call (tree function, tree params)
2798 return cp_build_function_call (function, params, tf_warning_or_error);
2802 cp_build_function_call (tree function, tree params, tsubst_flags_t complain)
2804 tree fntype, fndecl;
2805 tree name = NULL_TREE;
2807 tree original = function;
2808 int nargs, parm_types_len;
2812 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2813 expressions, like those used for ObjC messenger dispatches. */
2814 function = objc_rewrite_function_call (function, params);
2816 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2817 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2818 if (TREE_CODE (function) == NOP_EXPR
2819 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2820 function = TREE_OPERAND (function, 0);
2822 if (TREE_CODE (function) == FUNCTION_DECL)
2824 name = DECL_NAME (function);
2826 mark_used (function);
2829 /* Convert anything with function type to a pointer-to-function. */
2830 if (DECL_MAIN_P (function) && (complain & tf_error))
2831 pedwarn (input_location, OPT_pedantic,
2832 "ISO C++ forbids calling %<::main%> from within program");
2834 function = build_addr_func (function);
2840 function = build_addr_func (function);
2843 if (function == error_mark_node)
2844 return error_mark_node;
2846 fntype = TREE_TYPE (function);
2848 if (TYPE_PTRMEMFUNC_P (fntype))
2850 if (complain & tf_error)
2851 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2852 "function in %<%E (...)%>, e.g. %<(... ->* %E) (...)%>",
2853 original, original);
2854 return error_mark_node;
2857 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2858 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2860 if (!((TREE_CODE (fntype) == POINTER_TYPE
2861 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2863 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2865 if (complain & tf_error)
2866 error ("%qE cannot be used as a function", original);
2867 return error_mark_node;
2870 /* fntype now gets the type of function pointed to. */
2871 fntype = TREE_TYPE (fntype);
2872 parm_types = TYPE_ARG_TYPES (fntype);
2874 /* Allocate storage for converted arguments. */
2875 parm_types_len = list_length (parm_types);
2876 nargs = list_length (params);
2877 if (parm_types_len > nargs)
2878 nargs = parm_types_len;
2879 argarray = (tree *) alloca (nargs * sizeof (tree));
2881 /* Convert the parameters to the types declared in the
2882 function prototype, or apply default promotions. */
2883 nargs = convert_arguments (nargs, argarray, parm_types,
2884 params, fndecl, LOOKUP_NORMAL,
2887 return error_mark_node;
2889 /* Check for errors in format strings and inappropriately
2891 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2894 return build_cxx_call (function, nargs, argarray);
2897 /* Convert the actual parameter expressions in the list VALUES
2898 to the types in the list TYPELIST.
2899 If parmdecls is exhausted, or when an element has NULL as its type,
2900 perform the default conversions.
2902 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2904 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2906 This is also where warnings about wrong number of args are generated.
2908 Returns the actual number of arguments processed (which might be less
2909 than NARGS), or -1 on error.
2911 VALUES is a chain of TREE_LIST nodes with the elements of the list
2912 in the TREE_VALUE slots of those nodes.
2914 In C++, unspecified trailing parameters can be filled in with their
2915 default arguments, if such were specified. Do so here. */
2918 convert_arguments (int nargs, tree *argarray,
2919 tree typelist, tree values, tree fndecl, int flags,
2920 tsubst_flags_t complain)
2922 tree typetail, valtail;
2923 const char *called_thing = 0;
2926 /* Argument passing is always copy-initialization. */
2927 flags |= LOOKUP_ONLYCONVERTING;
2931 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2933 if (DECL_NAME (fndecl) == NULL_TREE
2934 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2935 called_thing = "constructor";
2937 called_thing = "member function";
2940 called_thing = "function";
2943 for (valtail = values, typetail = typelist;
2945 valtail = TREE_CHAIN (valtail), i++)
2947 tree type = typetail ? TREE_VALUE (typetail) : 0;
2948 tree val = TREE_VALUE (valtail);
2950 if (val == error_mark_node || type == error_mark_node)
2953 if (type == void_type_node)
2955 if (complain & tf_error)
2959 error ("too many arguments to %s %q+#D",
2960 called_thing, fndecl);
2961 error ("at this point in file");
2964 error ("too many arguments to function");
2971 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2972 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2973 if (TREE_CODE (val) == NOP_EXPR
2974 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2975 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2976 val = TREE_OPERAND (val, 0);
2978 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2980 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2981 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2982 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2983 val = decay_conversion (val);
2986 if (val == error_mark_node)
2991 /* Formal parm type is specified by a function prototype. */
2994 if (!COMPLETE_TYPE_P (complete_type (type)))
2996 if (complain & tf_error)
2999 error ("parameter %P of %qD has incomplete type %qT",
3002 error ("parameter %P has incomplete type %qT", i, type);
3004 parmval = error_mark_node;
3008 parmval = convert_for_initialization
3009 (NULL_TREE, type, val, flags,
3010 "argument passing", fndecl, i, complain);
3011 parmval = convert_for_arg_passing (type, parmval);
3014 if (parmval == error_mark_node)
3017 argarray[i] = parmval;
3021 if (fndecl && DECL_BUILT_IN (fndecl)
3022 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3023 /* Don't do ellipsis conversion for __built_in_constant_p
3024 as this will result in spurious warnings for non-POD
3026 val = require_complete_type (val);
3028 val = convert_arg_to_ellipsis (val);
3034 typetail = TREE_CHAIN (typetail);
3037 if (typetail != 0 && typetail != void_list_node)
3039 /* See if there are default arguments that can be used. Because
3040 we hold default arguments in the FUNCTION_TYPE (which is so
3041 wrong), we can see default parameters here from deduced
3042 contexts (and via typeof) for indirect function calls.
3043 Fortunately we know whether we have a function decl to
3044 provide default arguments in a language conformant
3046 if (fndecl && TREE_PURPOSE (typetail)
3047 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3049 for (; typetail != void_list_node; ++i)
3052 = convert_default_arg (TREE_VALUE (typetail),
3053 TREE_PURPOSE (typetail),
3056 if (parmval == error_mark_node)
3059 argarray[i] = parmval;
3060 typetail = TREE_CHAIN (typetail);
3061 /* ends with `...'. */
3062 if (typetail == NULL_TREE)
3068 if (complain & tf_error)
3072 error ("too few arguments to %s %q+#D",
3073 called_thing, fndecl);
3074 error ("at this point in file");
3077 error ("too few arguments to function");
3083 gcc_assert (i <= nargs);
3087 /* Build a binary-operation expression, after performing default
3088 conversions on the operands. CODE is the kind of expression to
3089 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3090 are the tree codes which correspond to ARG1 and ARG2 when issuing
3091 warnings about possibly misplaced parentheses. They may differ
3092 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3093 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3094 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3095 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3096 ARG2_CODE as ERROR_MARK. */
3099 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3100 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3101 tsubst_flags_t complain)
3110 if (processing_template_decl)
3112 if (type_dependent_expression_p (arg1)
3113 || type_dependent_expression_p (arg2))
3114 return build_min_nt (code, arg1, arg2);
3115 arg1 = build_non_dependent_expr (arg1);
3116 arg2 = build_non_dependent_expr (arg2);
3119 if (code == DOTSTAR_EXPR)
3120 expr = build_m_component_ref (arg1, arg2);
3122 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3123 overloaded_p, complain);
3125 /* Check for cases such as x+y<<z which users are likely to
3126 misinterpret. But don't warn about obj << x + y, since that is a
3127 common idiom for I/O. */
3128 if (warn_parentheses
3129 && !processing_template_decl
3130 && !error_operand_p (arg1)
3131 && !error_operand_p (arg2)
3132 && (code != LSHIFT_EXPR
3133 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3134 warn_about_parentheses (code, arg1_code, arg2_code);
3136 if (processing_template_decl && expr != error_mark_node)
3137 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3142 /* For the c-common bits. */
3144 build_binary_op (enum tree_code code, tree op0, tree op1,
3145 int convert_p ATTRIBUTE_UNUSED)
3147 return cp_build_binary_op(code, op0, op1, tf_warning_or_error);
3151 /* Build a binary-operation expression without default conversions.
3152 CODE is the kind of expression to build.
3153 This function differs from `build' in several ways:
3154 the data type of the result is computed and recorded in it,
3155 warnings are generated if arg data types are invalid,
3156 special handling for addition and subtraction of pointers is known,
3157 and some optimization is done (operations on narrow ints
3158 are done in the narrower type when that gives the same result).
3159 Constant folding is also done before the result is returned.
3161 Note that the operands will never have enumeral types
3162 because either they have just had the default conversions performed
3163 or they have both just been converted to some other type in which
3164 the arithmetic is to be done.
3166 C++: must do special pointer arithmetic when implementing
3167 multiple inheritance, and deal with pointer to member functions. */
3170 cp_build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3171 tsubst_flags_t complain)
3174 enum tree_code code0, code1;
3176 const char *invalid_op_diag;
3178 /* Expression code to give to the expression when it is built.
3179 Normally this is CODE, which is what the caller asked for,
3180 but in some special cases we change it. */
3181 enum tree_code resultcode = code;
3183 /* Data type in which the computation is to be performed.
3184 In the simplest cases this is the common type of the arguments. */
3185 tree result_type = NULL;
3187 /* Nonzero means operands have already been type-converted
3188 in whatever way is necessary.
3189 Zero means they need to be converted to RESULT_TYPE. */
3192 /* Nonzero means create the expression with this type, rather than
3194 tree build_type = 0;
3196 /* Nonzero means after finally constructing the expression
3197 convert it to this type. */
3198 tree final_type = 0;
3202 /* Nonzero if this is an operation like MIN or MAX which can
3203 safely be computed in short if both args are promoted shorts.
3204 Also implies COMMON.
3205 -1 indicates a bitwise operation; this makes a difference
3206 in the exact conditions for when it is safe to do the operation
3207 in a narrower mode. */
3210 /* Nonzero if this is a comparison operation;
3211 if both args are promoted shorts, compare the original shorts.
3212 Also implies COMMON. */
3213 int short_compare = 0;
3215 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3218 /* True if both operands have arithmetic type. */
3219 bool arithmetic_types_p;
3221 /* Apply default conversions. */
3225 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3226 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3227 || code == TRUTH_XOR_EXPR)
3229 if (!really_overloaded_fn (op0))
3230 op0 = decay_conversion (op0);
3231 if (!really_overloaded_fn (op1))
3232 op1 = decay_conversion (op1);
3236 if (!really_overloaded_fn (op0))
3237 op0 = default_conversion (op0);
3238 if (!really_overloaded_fn (op1))
3239 op1 = default_conversion (op1);
3242 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3243 STRIP_TYPE_NOPS (op0);
3244 STRIP_TYPE_NOPS (op1);
3246 /* DTRT if one side is an overloaded function, but complain about it. */
3247 if (type_unknown_p (op0))
3249 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3250 if (t != error_mark_node)
3252 if (complain & tf_error)
3253 permerror (input_location, "assuming cast to type %qT from overloaded function",
3258 if (type_unknown_p (op1))
3260 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3261 if (t != error_mark_node)
3263 if (complain & tf_error)
3264 permerror (input_location, "assuming cast to type %qT from overloaded function",
3270 type0 = TREE_TYPE (op0);
3271 type1 = TREE_TYPE (op1);
3273 /* The expression codes of the data types of the arguments tell us
3274 whether the arguments are integers, floating, pointers, etc. */
3275 code0 = TREE_CODE (type0);
3276 code1 = TREE_CODE (type1);
3278 /* If an error was already reported for one of the arguments,
3279 avoid reporting another error. */
3281 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3282 return error_mark_node;
3284 if ((invalid_op_diag
3285 = targetm.invalid_binary_op (code, type0, type1)))
3287 error (invalid_op_diag);
3288 return error_mark_node;
3294 /* Subtraction of two similar pointers.
3295 We must subtract them as integers, then divide by object size. */
3296 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3297 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3299 return pointer_diff (op0, op1, common_type (type0, type1));
3300 /* In all other cases except pointer - int, the usual arithmetic
3302 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3307 /* The pointer - int case is just like pointer + int; fall
3310 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3311 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3315 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3316 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3317 if (processing_template_decl)
3319 result_type = TREE_TYPE (ptr_operand);
3322 return cp_pointer_int_sum (code,
3333 case TRUNC_DIV_EXPR:
3335 case FLOOR_DIV_EXPR:
3336 case ROUND_DIV_EXPR:
3337 case EXACT_DIV_EXPR:
3338 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3339 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3340 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3341 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3343 enum tree_code tcode0 = code0, tcode1 = code1;
3345 warn_for_div_by_zero (op1);
3347 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3348 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3349 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3350 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3352 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3353 resultcode = RDIV_EXPR;
3355 /* When dividing two signed integers, we have to promote to int.
3356 unless we divide by a constant != -1. Note that default
3357 conversion will have been performed on the operands at this
3358 point, so we have to dig out the original type to find out if
3360 shorten = ((TREE_CODE (op0) == NOP_EXPR
3361 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3362 || (TREE_CODE (op1) == INTEGER_CST
3363 && ! integer_all_onesp (op1)));
3372 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3373 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3374 && !VECTOR_FLOAT_TYPE_P (type0)
3375 && !VECTOR_FLOAT_TYPE_P (type1)))
3379 case TRUNC_MOD_EXPR:
3380 case FLOOR_MOD_EXPR:
3381 warn_for_div_by_zero (op1);
3383 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3385 /* Although it would be tempting to shorten always here, that loses
3386 on some targets, since the modulo instruction is undefined if the
3387 quotient can't be represented in the computation mode. We shorten
3388 only if unsigned or if dividing by something we know != -1. */
3389 shorten = ((TREE_CODE (op0) == NOP_EXPR
3390 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3391 || (TREE_CODE (op1) == INTEGER_CST
3392 && ! integer_all_onesp (op1)));
3397 case TRUTH_ANDIF_EXPR:
3398 case TRUTH_ORIF_EXPR:
3399 case TRUTH_AND_EXPR:
3401 result_type = boolean_type_node;
3404 /* Shift operations: result has same type as first operand;
3405 always convert second operand to int.
3406 Also set SHORT_SHIFT if shifting rightward. */
3409 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3411 result_type = type0;
3412 if (TREE_CODE (op1) == INTEGER_CST)
3414 if (tree_int_cst_lt (op1, integer_zero_node))
3416 if (complain & tf_warning)
3417 warning (0, "right shift count is negative");
3421 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3422 && (complain & tf_warning))
3423 warning (0, "right shift count >= width of type");
3426 /* Convert the shift-count to an integer, regardless of
3427 size of value being shifted. */
3428 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3429 op1 = cp_convert (integer_type_node, op1);
3430 /* Avoid converting op1 to result_type later. */
3436 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3438 result_type = type0;
3439 if (TREE_CODE (op1) == INTEGER_CST)
3441 if (tree_int_cst_lt (op1, integer_zero_node))
3443 if (complain & tf_warning)
3444 warning (0, "left shift count is negative");
3446 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3448 if (complain & tf_warning)
3449 warning (0, "left shift count >= width of type");
3452 /* Convert the shift-count to an integer, regardless of
3453 size of value being shifted. */
3454 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3455 op1 = cp_convert (integer_type_node, op1);
3456 /* Avoid converting op1 to result_type later. */
3463 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3465 result_type = type0;
3466 if (TREE_CODE (op1) == INTEGER_CST)
3468 if (tree_int_cst_lt (op1, integer_zero_node))
3470 if (complain & tf_warning)
3471 warning (0, (code == LROTATE_EXPR)
3472 ? G_("left rotate count is negative")
3473 : G_("right rotate count is negative"));
3475 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3477 if (complain & tf_warning)
3478 warning (0, (code == LROTATE_EXPR)
3479 ? G_("left rotate count >= width of type")
3480 : G_("right rotate count >= width of type"));
3483 /* Convert the shift-count to an integer, regardless of
3484 size of value being shifted. */
3485 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3486 op1 = cp_convert (integer_type_node, op1);
3492 if ((complain & tf_warning)
3493 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3494 warning (OPT_Wfloat_equal,
3495 "comparing floating point with == or != is unsafe");
3496 if ((complain & tf_warning)
3497 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3498 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3499 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3501 build_type = boolean_type_node;
3502 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3503 || code0 == COMPLEX_TYPE)
3504 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3505 || code1 == COMPLEX_TYPE))
3507 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3508 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3509 result_type = composite_pointer_type (type0, type1, op0, op1,
3510 "comparison", complain);
3511 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3512 && null_ptr_cst_p (op1))
3514 if (TREE_CODE (op0) == ADDR_EXPR
3515 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3517 if (complain & tf_warning)
3518 warning (OPT_Waddress, "the address of %qD will never be NULL",
3519 TREE_OPERAND (op0, 0));
3521 result_type = type0;
3523 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3524 && null_ptr_cst_p (op0))
3526 if (TREE_CODE (op1) == ADDR_EXPR
3527 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3529 if (complain & tf_warning)
3530 warning (OPT_Waddress, "the address of %qD will never be NULL",
3531 TREE_OPERAND (op1, 0));
3533 result_type = type1;
3535 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3537 result_type = type0;
3538 if (complain & tf_error)
3539 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3541 return error_mark_node;
3543 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3545 result_type = type1;
3546 if (complain & tf_error)
3547 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3549 return error_mark_node;
3551 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3553 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3554 == ptrmemfunc_vbit_in_delta)
3556 tree pfn0 = pfn_from_ptrmemfunc (op0);
3557 tree delta0 = delta_from_ptrmemfunc (op0);
3558 tree e1 = cp_build_binary_op (EQ_EXPR,
3560 fold_convert (TREE_TYPE (pfn0),
3563 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3567 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3569 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2,
3571 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3575 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3576 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3578 result_type = TREE_TYPE (op0);
3580 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3581 return cp_build_binary_op (code, op1, op0, complain);
3582 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3585 /* E will be the final comparison. */
3587 /* E1 and E2 are for scratch. */
3595 type = composite_pointer_type (type0, type1, op0, op1, "comparison",
3598 if (!same_type_p (TREE_TYPE (op0), type))
3599 op0 = cp_convert_and_check (type, op0);
3600 if (!same_type_p (TREE_TYPE (op1), type))
3601 op1 = cp_convert_and_check (type, op1);
3603 if (op0 == error_mark_node || op1 == error_mark_node)
3604 return error_mark_node;
3606 if (TREE_SIDE_EFFECTS (op0))
3607 op0 = save_expr (op0);
3608 if (TREE_SIDE_EFFECTS (op1))
3609 op1 = save_expr (op1);
3611 pfn0 = pfn_from_ptrmemfunc (op0);
3612 pfn1 = pfn_from_ptrmemfunc (op1);
3613 delta0 = delta_from_ptrmemfunc (op0);
3614 delta1 = delta_from_ptrmemfunc (op1);
3615 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3616 == ptrmemfunc_vbit_in_delta)
3621 && ((op0.delta == op1.delta)
3622 || (!op0.pfn && op0.delta & 1 == 0
3623 && op1.delta & 1 == 0))
3625 The reason for the `!op0.pfn' bit is that a NULL
3626 pointer-to-member is any member with a zero PFN and
3627 LSB of the DELTA field is 0. */
3629 e1 = cp_build_binary_op (BIT_AND_EXPR,
3633 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node,
3635 e2 = cp_build_binary_op (BIT_AND_EXPR,
3639 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3641 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1,
3643 e2 = cp_build_binary_op (EQ_EXPR,
3645 fold_convert (TREE_TYPE (pfn0),
3648 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3649 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3650 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3657 && (!op0.pfn || op0.delta == op1.delta))
3659 The reason for the `!op0.pfn' bit is that a NULL
3660 pointer-to-member is any member with a zero PFN; the
3661 DELTA field is unspecified. */
3663 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3664 e2 = cp_build_binary_op (EQ_EXPR,
3666 fold_convert (TREE_TYPE (pfn0),
3669 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3671 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3672 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3673 if (code == EQ_EXPR)
3675 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node, complain);
3679 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3680 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3682 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3683 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3691 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3692 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3694 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3695 result_type = composite_pointer_type (type0, type1, op0, op1,
3696 "comparison", complain);
3703 if (TREE_CODE (orig_op0) == STRING_CST
3704 || TREE_CODE (orig_op1) == STRING_CST)
3706 if (complain & tf_warning)
3707 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3710 build_type = boolean_type_node;
3711 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3712 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3714 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3715 result_type = composite_pointer_type (type0, type1, op0, op1,
3716 "comparison", complain);
3717 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3718 && integer_zerop (op1))
3719 result_type = type0;
3720 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3721 && integer_zerop (op0))
3722 result_type = type1;
3723 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3725 result_type = type0;
3726 if (complain & tf_error)
3727 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3729 return error_mark_node;
3731 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3733 result_type = type1;
3734 if (complain & tf_error)
3735 permerror (input_location, "ISO C++ forbids comparison between pointer and integer");
3737 return error_mark_node;
3741 case UNORDERED_EXPR:
3748 build_type = integer_type_node;
3749 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3751 if (complain & tf_error)
3752 error ("unordered comparison on non-floating point argument");
3753 return error_mark_node;
3762 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3763 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3764 || code1 == COMPLEX_TYPE)))
3765 arithmetic_types_p = 1;
3768 arithmetic_types_p = 0;
3769 /* Vector arithmetic is only allowed when both sides are vectors. */
3770 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3772 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3773 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3776 binary_op_error (code, type0, type1);
3777 return error_mark_node;
3779 arithmetic_types_p = 1;
3782 /* Determine the RESULT_TYPE, if it is not already known. */
3784 && arithmetic_types_p
3785 && (shorten || common || short_compare))
3786 result_type = common_type (type0, type1);
3790 if (complain & tf_error)
3791 error ("invalid operands of types %qT and %qT to binary %qO",
3792 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3793 return error_mark_node;
3796 /* If we're in a template, the only thing we need to know is the
3798 if (processing_template_decl)
3800 /* Since the middle-end checks the type when doing a build2, we
3801 need to build the tree in pieces. This built tree will never
3802 get out of the front-end as we replace it when instantiating
3804 tree tmp = build2 (resultcode,
3805 build_type ? build_type : result_type,
3807 TREE_OPERAND (tmp, 0) = op0;
3811 if (arithmetic_types_p)
3813 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3815 /* For certain operations (which identify themselves by shorten != 0)
3816 if both args were extended from the same smaller type,
3817 do the arithmetic in that type and then extend.
3819 shorten !=0 and !=1 indicates a bitwise operation.
3820 For them, this optimization is safe only if
3821 both args are zero-extended or both are sign-extended.
3822 Otherwise, we might change the result.
3823 E.g., (short)-1 | (unsigned short)-1 is (int)-1
3824 but calculated in (unsigned short) it would be (unsigned short)-1. */
3826 if (shorten && none_complex)
3828 final_type = result_type;
3829 result_type = shorten_binary_op (result_type, op0, op1,
3833 /* Comparison operations are shortened too but differently.
3834 They identify themselves by setting short_compare = 1. */
3838 /* Don't write &op0, etc., because that would prevent op0
3839 from being kept in a register.
3840 Instead, make copies of the our local variables and
3841 pass the copies by reference, then copy them back afterward. */
3842 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3843 enum tree_code xresultcode = resultcode;
3845 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3847 return cp_convert (boolean_type_node, val);
3848 op0 = xop0, op1 = xop1;
3850 resultcode = xresultcode;
3853 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3854 && warn_sign_compare
3855 /* Do not warn until the template is instantiated; we cannot
3856 bound the ranges of the arguments until that point. */
3857 && !processing_template_decl
3858 && (complain & tf_warning))
3860 warn_for_sign_compare (orig_op0, orig_op1, op0, op1,
3861 result_type, resultcode);
3865 /* Issue warnings about peculiar, but valid, uses of NULL. */
3866 if ((orig_op0 == null_node || orig_op1 == null_node)
3867 /* It's reasonable to use pointer values as operands of &&
3868 and ||, so NULL is no exception. */
3869 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3870 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3871 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3872 && code != EQ_EXPR && code != NE_EXPR)
3873 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3874 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3875 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE))
3876 && (complain & tf_warning))
3877 /* Some sort of arithmetic operation involving NULL was
3878 performed. Note that pointer-difference and pointer-addition
3879 have already been handled above, and so we don't end up here in
3881 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3884 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3885 Then the expression will be built.
3886 It will be given type FINAL_TYPE if that is nonzero;
3887 otherwise, it will be given type RESULT_TYPE. */
3890 if (TREE_TYPE (op0) != result_type)
3891 op0 = cp_convert_and_check (result_type, op0);
3892 if (TREE_TYPE (op1) != result_type)
3893 op1 = cp_convert_and_check (result_type, op1);
3895 if (op0 == error_mark_node || op1 == error_mark_node)
3896 return error_mark_node;
3899 if (build_type == NULL_TREE)
3900 build_type = result_type;
3902 result = build2 (resultcode, build_type, op0, op1);
3903 result = fold_if_not_in_template (result);
3904 if (final_type != 0)
3905 result = cp_convert (final_type, result);
3907 if (TREE_OVERFLOW_P (result)
3908 && !TREE_OVERFLOW_P (op0)
3909 && !TREE_OVERFLOW_P (op1))
3910 overflow_warning (result);
3915 /* Return a tree for the sum or difference (RESULTCODE says which)
3916 of pointer PTROP and integer INTOP. */
3919 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3921 tree res_type = TREE_TYPE (ptrop);
3923 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3924 in certain circumstance (when it's valid to do so). So we need
3925 to make sure it's complete. We don't need to check here, if we
3926 can actually complete it at all, as those checks will be done in
3927 pointer_int_sum() anyway. */
3928 complete_type (TREE_TYPE (res_type));
3930 return pointer_int_sum (resultcode, ptrop,
3931 fold_if_not_in_template (intop));
3934 /* Return a tree for the difference of pointers OP0 and OP1.
3935 The resulting tree has type int. */
3938 pointer_diff (tree op0, tree op1, tree ptrtype)
3941 tree restype = ptrdiff_type_node;
3942 tree target_type = TREE_TYPE (ptrtype);
3944 if (!complete_type_or_else (target_type, NULL_TREE))
3945 return error_mark_node;
3947 if (TREE_CODE (target_type) == VOID_TYPE)
3948 permerror (input_location, "ISO C++ forbids using pointer of type %<void *%> in subtraction");
3949 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3950 permerror (input_location, "ISO C++ forbids using pointer to a function in subtraction");
3951 if (TREE_CODE (target_type) == METHOD_TYPE)
3952 permerror (input_location, "ISO C++ forbids using pointer to a method in subtraction");
3954 /* First do the subtraction as integers;
3955 then drop through to build the divide operator. */
3957 op0 = cp_build_binary_op (MINUS_EXPR,
3958 cp_convert (restype, op0),
3959 cp_convert (restype, op1),
3960 tf_warning_or_error);
3962 /* This generates an error if op1 is a pointer to an incomplete type. */
3963 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3964 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3966 op1 = (TYPE_PTROB_P (ptrtype)
3967 ? size_in_bytes (target_type)
3968 : integer_one_node);
3970 /* Do the division. */
3972 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3973 return fold_if_not_in_template (result);
3976 /* Construct and perhaps optimize a tree representation
3977 for a unary operation. CODE, a tree_code, specifies the operation
3978 and XARG is the operand. */
3981 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
3983 tree orig_expr = xarg;
3987 if (processing_template_decl)
3989 if (type_dependent_expression_p (xarg))
3990 return build_min_nt (code, xarg, NULL_TREE);
3992 xarg = build_non_dependent_expr (xarg);
3997 /* [expr.unary.op] says:
3999 The address of an object of incomplete type can be taken.
4001 (And is just the ordinary address operator, not an overloaded
4002 "operator &".) However, if the type is a template
4003 specialization, we must complete the type at this point so that
4004 an overloaded "operator &" will be available if required. */
4005 if (code == ADDR_EXPR
4006 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
4007 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
4008 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
4009 || (TREE_CODE (xarg) == OFFSET_REF)))
4010 /* Don't look for a function. */;
4012 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4013 /*overloaded_p=*/NULL, complain);
4014 if (!exp && code == ADDR_EXPR)
4016 /* A pointer to member-function can be formed only by saying
4018 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4019 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4021 if (TREE_CODE (xarg) != OFFSET_REF
4022 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4024 error ("invalid use of %qE to form a pointer-to-member-function",
4026 if (TREE_CODE (xarg) != OFFSET_REF)
4027 inform (input_location, " a qualified-id is required");
4028 return error_mark_node;
4032 error ("parentheses around %qE cannot be used to form a"
4033 " pointer-to-member-function",
4035 PTRMEM_OK_P (xarg) = 1;
4039 if (TREE_CODE (xarg) == OFFSET_REF)
4041 ptrmem = PTRMEM_OK_P (xarg);
4043 if (!ptrmem && !flag_ms_extensions
4044 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4046 /* A single non-static member, make sure we don't allow a
4047 pointer-to-member. */
4048 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4049 TREE_OPERAND (xarg, 0),
4050 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4051 PTRMEM_OK_P (xarg) = ptrmem;
4054 else if (TREE_CODE (xarg) == TARGET_EXPR && (complain & tf_warning))
4055 warning (0, "taking address of temporary");
4056 exp = cp_build_unary_op (ADDR_EXPR, xarg, 0, complain);
4059 if (processing_template_decl && exp != error_mark_node)
4060 exp = build_min_non_dep (code, exp, orig_expr,
4061 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4062 if (TREE_CODE (exp) == ADDR_EXPR)
4063 PTRMEM_OK_P (exp) = ptrmem;
4067 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4068 constants, where a null value is represented by an INTEGER_CST of
4072 cp_truthvalue_conversion (tree expr)
4074 tree type = TREE_TYPE (expr);
4075 if (TYPE_PTRMEM_P (type))
4076 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4078 return c_common_truthvalue_conversion (expr);
4081 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4084 condition_conversion (tree expr)
4087 if (processing_template_decl)
4089 t = perform_implicit_conversion (boolean_type_node, expr,
4090 tf_warning_or_error);
4091 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4095 /* Return an ADDR_EXPR giving the address of T. This function
4096 attempts no optimizations or simplifications; it is a low-level
4100 build_address (tree t)
4104 if (error_operand_p (t) || !cxx_mark_addressable (t))
4105 return error_mark_node;
4107 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4112 /* Return a NOP_EXPR converting EXPR to TYPE. */
4115 build_nop (tree type, tree expr)
4117 if (type == error_mark_node || error_operand_p (expr))
4119 return build1 (NOP_EXPR, type, expr);
4122 /* C++: Must handle pointers to members.
4124 Perhaps type instantiation should be extended to handle conversion
4125 from aggregates to types we don't yet know we want? (Or are those
4126 cases typically errors which should be reported?)
4128 NOCONVERT nonzero suppresses the default promotions
4129 (such as from short to int). */
4132 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4133 tsubst_flags_t complain)
4135 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4138 const char *errstring = NULL;
4140 const char *invalid_op_diag;
4142 if (arg == error_mark_node)
4143 return error_mark_node;
4145 if ((invalid_op_diag
4146 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4151 error (invalid_op_diag);
4152 return error_mark_node;
4157 case UNARY_PLUS_EXPR:
4160 int flags = WANT_ARITH | WANT_ENUM;
4161 /* Unary plus (but not unary minus) is allowed on pointers. */
4162 if (code == UNARY_PLUS_EXPR)
4163 flags |= WANT_POINTER;
4164 arg = build_expr_type_conversion (flags, arg, true);
4166 errstring = (code == NEGATE_EXPR
4167 ? "wrong type argument to unary minus"
4168 : "wrong type argument to unary plus");
4171 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4172 arg = perform_integral_promotions (arg);
4174 /* Make sure the result is not an lvalue: a unary plus or minus
4175 expression is always a rvalue. */
4182 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4186 arg = default_conversion (arg);
4188 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4191 errstring = "wrong type argument to bit-complement";
4192 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4193 arg = perform_integral_promotions (arg);
4197 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4198 errstring = "wrong type argument to abs";
4199 else if (!noconvert)
4200 arg = default_conversion (arg);
4204 /* Conjugating a real value is a no-op, but allow it anyway. */
4205 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4206 errstring = "wrong type argument to conjugation";
4207 else if (!noconvert)
4208 arg = default_conversion (arg);
4211 case TRUTH_NOT_EXPR:
4212 arg = perform_implicit_conversion (boolean_type_node, arg,
4214 val = invert_truthvalue (arg);
4215 if (arg != error_mark_node)
4217 errstring = "in argument to unary !";
4224 if (TREE_CODE (arg) == COMPLEX_CST)
4225 return TREE_REALPART (arg);
4226 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4228 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4229 return fold_if_not_in_template (arg);
4235 if (TREE_CODE (arg) == COMPLEX_CST)
4236 return TREE_IMAGPART (arg);
4237 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4239 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4240 return fold_if_not_in_template (arg);
4243 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4245 case PREINCREMENT_EXPR:
4246 case POSTINCREMENT_EXPR:
4247 case PREDECREMENT_EXPR:
4248 case POSTDECREMENT_EXPR:
4249 /* Handle complex lvalues (when permitted)
4250 by reduction to simpler cases. */
4252 val = unary_complex_lvalue (code, arg);
4256 /* Increment or decrement the real part of the value,
4257 and don't change the imaginary part. */
4258 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4262 arg = stabilize_reference (arg);
4263 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
4264 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
4265 real = cp_build_unary_op (code, real, 1, complain);
4266 if (real == error_mark_node || imag == error_mark_node)
4267 return error_mark_node;
4268 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4272 /* Report invalid types. */
4274 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4277 if (code == PREINCREMENT_EXPR)
4278 errstring ="no pre-increment operator for type";
4279 else if (code == POSTINCREMENT_EXPR)
4280 errstring ="no post-increment operator for type";
4281 else if (code == PREDECREMENT_EXPR)
4282 errstring ="no pre-decrement operator for type";
4284 errstring ="no post-decrement operator for type";
4287 else if (arg == error_mark_node)
4288 return error_mark_node;
4290 /* Report something read-only. */
4292 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4293 || TREE_READONLY (arg))
4295 if (complain & tf_error)
4296 readonly_error (arg, ((code == PREINCREMENT_EXPR
4297 || code == POSTINCREMENT_EXPR)
4298 ? "increment" : "decrement"));
4300 return error_mark_node;
4306 tree result_type = TREE_TYPE (arg);
4308 declared_type = unlowered_expr_type (arg);
4310 arg = get_unwidened (arg, 0);
4311 argtype = TREE_TYPE (arg);
4313 /* ARM $5.2.5 last annotation says this should be forbidden. */
4314 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4316 if (complain & tf_error)
4317 permerror (input_location, (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4318 ? G_("ISO C++ forbids incrementing an enum")
4319 : G_("ISO C++ forbids decrementing an enum"));
4321 return error_mark_node;
4324 /* Compute the increment. */
4326 if (TREE_CODE (argtype) == POINTER_TYPE)
4328 tree type = complete_type (TREE_TYPE (argtype));
4330 if (!COMPLETE_OR_VOID_TYPE_P (type))
4332 if (complain & tf_error)
4333 error (((code == PREINCREMENT_EXPR
4334 || code == POSTINCREMENT_EXPR))
4335 ? G_("cannot increment a pointer to incomplete type %qT")
4336 : G_("cannot decrement a pointer to incomplete type %qT"),
4337 TREE_TYPE (argtype));
4339 return error_mark_node;
4341 else if ((pedantic || warn_pointer_arith)
4342 && !TYPE_PTROB_P (argtype))
4344 if (complain & tf_error)
4345 permerror (input_location, (code == PREINCREMENT_EXPR
4346 || code == POSTINCREMENT_EXPR)
4347 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4348 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4351 return error_mark_node;
4354 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4357 inc = integer_one_node;
4359 inc = cp_convert (argtype, inc);
4361 /* Complain about anything else that is not a true lvalue. */
4362 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4363 || code == POSTINCREMENT_EXPR)
4364 ? lv_increment : lv_decrement),
4366 return error_mark_node;
4368 /* Forbid using -- on `bool'. */
4369 if (same_type_p (declared_type, boolean_type_node))
4371 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4373 if (complain & tf_error)
4374 error ("invalid use of Boolean expression as operand "
4375 "to %<operator--%>");
4376 return error_mark_node;
4378 val = boolean_increment (code, arg);
4381 val = build2 (code, TREE_TYPE (arg), arg, inc);
4383 TREE_SIDE_EFFECTS (val) = 1;
4384 return cp_convert (result_type, val);
4388 /* Note that this operation never does default_conversion
4389 regardless of NOCONVERT. */
4391 argtype = lvalue_type (arg);
4393 if (TREE_CODE (arg) == OFFSET_REF)
4396 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4398 tree type = build_pointer_type (TREE_TYPE (argtype));
4399 arg = build1 (CONVERT_EXPR, type, arg);
4402 else if (DECL_MAIN_P (arg))
4405 if (complain & tf_error)
4406 permerror (input_location, "ISO C++ forbids taking address of function %<::main%>");
4408 return error_mark_node;
4411 /* Let &* cancel out to simplify resulting code. */
4412 if (TREE_CODE (arg) == INDIRECT_REF)
4414 /* We don't need to have `current_class_ptr' wrapped in a
4415 NON_LVALUE_EXPR node. */
4416 if (arg == current_class_ref)
4417 return current_class_ptr;
4419 arg = TREE_OPERAND (arg, 0);
4420 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4422 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4423 arg = build1 (CONVERT_EXPR, type, arg);
4426 /* Don't let this be an lvalue. */
4431 /* Uninstantiated types are all functions. Taking the
4432 address of a function is a no-op, so just return the
4435 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4436 || !IDENTIFIER_OPNAME_P (arg));
4438 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4439 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4441 /* They're trying to take the address of a unique non-static
4442 member function. This is ill-formed (except in MS-land),
4443 but let's try to DTRT.
4444 Note: We only handle unique functions here because we don't
4445 want to complain if there's a static overload; non-unique
4446 cases will be handled by instantiate_type. But we need to
4447 handle this case here to allow casts on the resulting PMF.
4448 We could defer this in non-MS mode, but it's easier to give
4449 a useful error here. */
4451 /* Inside constant member functions, the `this' pointer
4452 contains an extra const qualifier. TYPE_MAIN_VARIANT
4453 is used here to remove this const from the diagnostics
4454 and the created OFFSET_REF. */
4455 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4456 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4459 if (! flag_ms_extensions)
4461 tree name = DECL_NAME (fn);
4462 if (!(complain & tf_error))
4463 return error_mark_node;
4464 else if (current_class_type
4465 && TREE_OPERAND (arg, 0) == current_class_ref)
4466 /* An expression like &memfn. */
4467 permerror (input_location, "ISO C++ forbids taking the address of an unqualified"
4468 " or parenthesized non-static member function to form"
4469 " a pointer to member function. Say %<&%T::%D%>",
4472 permerror (input_location, "ISO C++ forbids taking the address of a bound member"
4473 " function to form a pointer to member function."
4477 arg = build_offset_ref (base, fn, /*address_p=*/true);
4481 if (type_unknown_p (arg))
4482 return build1 (ADDR_EXPR, unknown_type_node, arg);
4484 /* Handle complex lvalues (when permitted)
4485 by reduction to simpler cases. */
4486 val = unary_complex_lvalue (code, arg);
4490 switch (TREE_CODE (arg))
4494 case FIX_TRUNC_EXPR:
4495 /* Even if we're not being pedantic, we cannot allow this
4496 extension when we're instantiating in a SFINAE
4498 if (! lvalue_p (arg) && complain == tf_none)
4500 if (complain & tf_error)
4501 permerror (input_location, "ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4503 return error_mark_node;
4508 arg = BASELINK_FUNCTIONS (arg);
4512 arg = OVL_CURRENT (arg);
4516 /* Turn a reference to a non-static data member into a
4517 pointer-to-member. */
4522 if (!PTRMEM_OK_P (arg))
4523 return cp_build_unary_op (code, arg, 0, complain);
4525 t = TREE_OPERAND (arg, 1);
4526 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4528 if (complain & tf_error)
4529 error ("cannot create pointer to reference member %qD", t);
4530 return error_mark_node;
4533 type = build_ptrmem_type (context_for_name_lookup (t),
4535 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4543 /* Anything not already handled and not a true memory reference
4545 if (TREE_CODE (argtype) != FUNCTION_TYPE
4546 && TREE_CODE (argtype) != METHOD_TYPE
4547 && TREE_CODE (arg) != OFFSET_REF
4548 && !lvalue_or_else (arg, lv_addressof, complain))
4549 return error_mark_node;
4551 if (argtype != error_mark_node)
4552 argtype = build_pointer_type (argtype);
4554 /* In a template, we are processing a non-dependent expression
4555 so we can just form an ADDR_EXPR with the correct type. */
4556 if (processing_template_decl || TREE_CODE (arg) != COMPONENT_REF)
4558 val = build_address (arg);
4559 if (TREE_CODE (arg) == OFFSET_REF)
4560 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4562 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4564 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4566 /* We can only get here with a single static member
4568 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4569 && DECL_STATIC_FUNCTION_P (fn));
4571 val = build_address (fn);
4572 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4573 /* Do not lose object's side effects. */
4574 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4575 TREE_OPERAND (arg, 0), val);
4577 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4579 if (complain & tf_error)
4580 error ("attempt to take address of bit-field structure member %qD",
4581 TREE_OPERAND (arg, 1));
4582 return error_mark_node;
4586 tree object = TREE_OPERAND (arg, 0);
4587 tree field = TREE_OPERAND (arg, 1);
4588 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4589 (TREE_TYPE (object), decl_type_context (field)));
4590 val = build_address (arg);
4593 if (TREE_CODE (argtype) == POINTER_TYPE
4594 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4596 build_ptrmemfunc_type (argtype);
4597 val = build_ptrmemfunc (argtype, val, 0,
4598 /*c_cast_p=*/false);
4610 argtype = TREE_TYPE (arg);
4611 return fold_if_not_in_template (build1 (code, argtype, arg));
4614 if (complain & tf_error)
4615 error ("%s", errstring);
4616 return error_mark_node;
4619 /* Hook for the c-common bits that build a unary op. */
4621 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4623 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
4626 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4627 for certain kinds of expressions which are not really lvalues
4628 but which we can accept as lvalues.
4630 If ARG is not a kind of expression we can handle, return
4634 unary_complex_lvalue (enum tree_code code, tree arg)
4636 /* Inside a template, making these kinds of adjustments is
4637 pointless; we are only concerned with the type of the
4639 if (processing_template_decl)
4642 /* Handle (a, b) used as an "lvalue". */
4643 if (TREE_CODE (arg) == COMPOUND_EXPR)
4645 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
4646 tf_warning_or_error);
4647 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4648 TREE_OPERAND (arg, 0), real_result);
4651 /* Handle (a ? b : c) used as an "lvalue". */
4652 if (TREE_CODE (arg) == COND_EXPR
4653 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4654 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
4656 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4657 if (TREE_CODE (arg) == MODIFY_EXPR
4658 || TREE_CODE (arg) == PREINCREMENT_EXPR
4659 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4661 tree lvalue = TREE_OPERAND (arg, 0);
4662 if (TREE_SIDE_EFFECTS (lvalue))
4664 lvalue = stabilize_reference (lvalue);
4665 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4666 lvalue, TREE_OPERAND (arg, 1));
4668 return unary_complex_lvalue
4669 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4672 if (code != ADDR_EXPR)
4675 /* Handle (a = b) used as an "lvalue" for `&'. */
4676 if (TREE_CODE (arg) == MODIFY_EXPR
4677 || TREE_CODE (arg) == INIT_EXPR)
4679 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
4680 tf_warning_or_error);
4681 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4683 TREE_NO_WARNING (arg) = 1;
4687 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4688 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4689 || TREE_CODE (arg) == OFFSET_REF)
4692 /* We permit compiler to make function calls returning
4693 objects of aggregate type look like lvalues. */
4697 if (TREE_CODE (targ) == SAVE_EXPR)
4698 targ = TREE_OPERAND (targ, 0);
4700 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
4702 if (TREE_CODE (arg) == SAVE_EXPR)
4705 targ = build_cplus_new (TREE_TYPE (arg), arg);
4706 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4709 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4710 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4711 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4714 /* Don't let anything else be handled specially. */
4718 /* Mark EXP saying that we need to be able to take the
4719 address of it; it should not be allocated in a register.
4720 Value is true if successful.
4722 C++: we do not allow `current_class_ptr' to be addressable. */
4725 cxx_mark_addressable (tree exp)
4730 switch (TREE_CODE (x))
4737 x = TREE_OPERAND (x, 0);
4741 if (x == current_class_ptr)
4743 error ("cannot take the address of %<this%>, which is an rvalue expression");
4744 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4750 /* Caller should not be trying to mark initialized
4751 constant fields addressable. */
4752 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4753 || DECL_IN_AGGR_P (x) == 0
4755 || DECL_EXTERNAL (x));
4760 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4761 && !DECL_ARTIFICIAL (x))
4763 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4766 ("address of explicit register variable %qD requested", x);
4769 else if (extra_warnings)
4771 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4773 TREE_ADDRESSABLE (x) = 1;
4777 TREE_ADDRESSABLE (x) = 1;
4781 TREE_ADDRESSABLE (x) = 1;
4785 TREE_ADDRESSABLE (x) = 1;
4786 cxx_mark_addressable (TREE_OPERAND (x, 0));
4794 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4797 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
4798 tsubst_flags_t complain)
4800 tree orig_ifexp = ifexp;
4801 tree orig_op1 = op1;
4802 tree orig_op2 = op2;
4805 if (processing_template_decl)
4807 /* The standard says that the expression is type-dependent if
4808 IFEXP is type-dependent, even though the eventual type of the
4809 expression doesn't dependent on IFEXP. */
4810 if (type_dependent_expression_p (ifexp)
4811 /* As a GNU extension, the middle operand may be omitted. */
4812 || (op1 && type_dependent_expression_p (op1))
4813 || type_dependent_expression_p (op2))
4814 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4815 ifexp = build_non_dependent_expr (ifexp);
4817 op1 = build_non_dependent_expr (op1);
4818 op2 = build_non_dependent_expr (op2);
4821 expr = build_conditional_expr (ifexp, op1, op2, complain);
4822 if (processing_template_decl && expr != error_mark_node)
4823 return build_min_non_dep (COND_EXPR, expr,
4824 orig_ifexp, orig_op1, orig_op2);
4828 /* Given a list of expressions, return a compound expression
4829 that performs them all and returns the value of the last of them. */
4831 tree build_x_compound_expr_from_list (tree list, const char *msg)
4833 tree expr = TREE_VALUE (list);
4835 if (TREE_CHAIN (list))
4838 permerror (input_location, "%s expression list treated as compound expression", msg);
4840 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4841 expr = build_x_compound_expr (expr, TREE_VALUE (list),
4842 tf_warning_or_error);
4848 /* Handle overloading of the ',' operator when needed. */
4851 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
4854 tree orig_op1 = op1;
4855 tree orig_op2 = op2;
4857 if (processing_template_decl)
4859 if (type_dependent_expression_p (op1)
4860 || type_dependent_expression_p (op2))
4861 return build_min_nt (COMPOUND_EXPR, op1, op2);
4862 op1 = build_non_dependent_expr (op1);
4863 op2 = build_non_dependent_expr (op2);
4866 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4867 /*overloaded_p=*/NULL, complain);
4869 result = cp_build_compound_expr (op1, op2, complain);
4871 if (processing_template_decl && result != error_mark_node)
4872 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4877 /* Like cp_build_compound_expr, but for the c-common bits. */
4880 build_compound_expr (tree lhs, tree rhs)
4882 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
4885 /* Build a compound expression. */
4888 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
4890 lhs = convert_to_void (lhs, "left-hand operand of comma", complain);
4892 if (lhs == error_mark_node || rhs == error_mark_node)
4893 return error_mark_node;
4895 if (TREE_CODE (rhs) == TARGET_EXPR)
4897 /* If the rhs is a TARGET_EXPR, then build the compound
4898 expression inside the target_expr's initializer. This
4899 helps the compiler to eliminate unnecessary temporaries. */
4900 tree init = TREE_OPERAND (rhs, 1);
4902 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4903 TREE_OPERAND (rhs, 1) = init;
4908 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4911 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4912 casts away constness. CAST gives the type of cast. */
4915 check_for_casting_away_constness (tree src_type, tree dest_type,
4916 enum tree_code cast)
4918 /* C-style casts are allowed to cast away constness. With
4919 WARN_CAST_QUAL, we still want to issue a warning. */
4920 if (cast == CAST_EXPR && !warn_cast_qual)
4923 if (casts_away_constness (src_type, dest_type))
4927 warning (OPT_Wcast_qual,
4928 "cast from type %qT to type %qT casts away constness",
4929 src_type, dest_type);
4932 case STATIC_CAST_EXPR:
4933 error ("static_cast from type %qT to type %qT casts away constness",
4934 src_type, dest_type);
4937 case REINTERPRET_CAST_EXPR:
4938 error ("reinterpret_cast from type %qT to type %qT casts away constness",
4939 src_type, dest_type);
4946 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4947 (another pointer-to-member type in the same hierarchy) and return
4948 the converted expression. If ALLOW_INVERSE_P is permitted, a
4949 pointer-to-derived may be converted to pointer-to-base; otherwise,
4950 only the other direction is permitted. If C_CAST_P is true, this
4951 conversion is taking place as part of a C-style cast. */
4954 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4957 if (TYPE_PTRMEM_P (type))
4961 if (TREE_CODE (expr) == PTRMEM_CST)
4962 expr = cplus_expand_constant (expr);
4963 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4964 TYPE_PTRMEM_CLASS_TYPE (type),
4967 if (!integer_zerop (delta))
4969 tree cond, op1, op2;
4971 cond = cp_build_binary_op (EQ_EXPR,
4973 build_int_cst (TREE_TYPE (expr), -1),
4974 tf_warning_or_error);
4975 op1 = build_nop (ptrdiff_type_node, expr);
4976 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta,
4977 tf_warning_or_error);
4979 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
4983 return build_nop (type, expr);
4986 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4987 allow_inverse_p, c_cast_p);
4990 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4991 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4992 Otherwise, return EXPR unchanged. */
4995 ignore_overflows (tree expr, tree orig)
4997 if (TREE_CODE (expr) == INTEGER_CST
4998 && CONSTANT_CLASS_P (orig)
4999 && TREE_CODE (orig) != STRING_CST
5000 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
5002 if (!TREE_OVERFLOW (orig))
5003 /* Ensure constant sharing. */
5004 expr = build_int_cst_wide (TREE_TYPE (expr),
5005 TREE_INT_CST_LOW (expr),
5006 TREE_INT_CST_HIGH (expr));
5009 /* Avoid clobbering a shared constant. */
5010 expr = copy_node (expr);
5011 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
5017 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5018 this static_cast is being attempted as one of the possible casts
5019 allowed by a C-style cast. (In that case, accessibility of base
5020 classes is not considered, and it is OK to cast away
5021 constness.) Return the result of the cast. *VALID_P is set to
5022 indicate whether or not the cast was valid. */
5025 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5026 bool *valid_p, tsubst_flags_t complain)
5032 /* Assume the cast is valid. */
5035 intype = TREE_TYPE (expr);
5037 /* Save casted types in the function's used types hash table. */
5038 used_types_insert (type);
5040 /* [expr.static.cast]
5042 An lvalue of type "cv1 B", where B is a class type, can be cast
5043 to type "reference to cv2 D", where D is a class derived (clause
5044 _class.derived_) from B, if a valid standard conversion from
5045 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5046 same cv-qualification as, or greater cv-qualification than, cv1,
5047 and B is not a virtual base class of D. */
5048 /* We check this case before checking the validity of "TYPE t =
5049 EXPR;" below because for this case:
5052 struct D : public B { D(const B&); };
5054 void f() { static_cast<const D&>(b); }
5056 we want to avoid constructing a new D. The standard is not
5057 completely clear about this issue, but our interpretation is
5058 consistent with other compilers. */
5059 if (TREE_CODE (type) == REFERENCE_TYPE
5060 && CLASS_TYPE_P (TREE_TYPE (type))
5061 && CLASS_TYPE_P (intype)
5062 && real_lvalue_p (expr)
5063 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5064 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5065 build_pointer_type (TYPE_MAIN_VARIANT
5066 (TREE_TYPE (type))))
5068 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5072 /* There is a standard conversion from "D*" to "B*" even if "B"
5073 is ambiguous or inaccessible. If this is really a
5074 static_cast, then we check both for inaccessibility and
5075 ambiguity. However, if this is a static_cast being performed
5076 because the user wrote a C-style cast, then accessibility is
5078 base = lookup_base (TREE_TYPE (type), intype,
5079 c_cast_p ? ba_unique : ba_check,
5082 /* Convert from "B*" to "D*". This function will check that "B"
5083 is not a virtual base of "D". */
5084 expr = build_base_path (MINUS_EXPR, build_address (expr),
5085 base, /*nonnull=*/false);
5086 /* Convert the pointer to a reference -- but then remember that
5087 there are no expressions with reference type in C++. */
5088 return convert_from_reference (build_nop (type, expr));
5093 /* [expr.static.cast]
5095 An expression e can be explicitly converted to a type T using a
5096 static_cast of the form static_cast<T>(e) if the declaration T
5097 t(e);" is well-formed, for some invented temporary variable
5099 result = perform_direct_initialization_if_possible (type, expr,
5100 c_cast_p, complain);
5103 result = convert_from_reference (result);
5105 /* Ignore any integer overflow caused by the cast. */
5106 result = ignore_overflows (result, orig);
5108 /* [expr.static.cast]
5110 If T is a reference type, the result is an lvalue; otherwise,
5111 the result is an rvalue. */
5112 if (TREE_CODE (type) != REFERENCE_TYPE)
5113 result = rvalue (result);
5117 /* [expr.static.cast]
5119 Any expression can be explicitly converted to type cv void. */
5120 if (TREE_CODE (type) == VOID_TYPE)
5121 return convert_to_void (expr, /*implicit=*/NULL, complain);
5123 /* [expr.static.cast]
5125 The inverse of any standard conversion sequence (clause _conv_),
5126 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5127 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5128 (_conv.bool_) conversions, can be performed explicitly using
5129 static_cast subject to the restriction that the explicit
5130 conversion does not cast away constness (_expr.const.cast_), and
5131 the following additional rules for specific cases: */
5132 /* For reference, the conversions not excluded are: integral
5133 promotions, floating point promotion, integral conversions,
5134 floating point conversions, floating-integral conversions,
5135 pointer conversions, and pointer to member conversions. */
5138 A value of integral _or enumeration_ type can be explicitly
5139 converted to an enumeration type. */
5140 /* The effect of all that is that any conversion between any two
5141 types which are integral, floating, or enumeration types can be
5143 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5144 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5146 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5148 /* Ignore any integer overflow caused by the cast. */
5149 expr = ignore_overflows (expr, orig);
5153 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5154 && CLASS_TYPE_P (TREE_TYPE (type))
5155 && CLASS_TYPE_P (TREE_TYPE (intype))
5156 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5157 (TREE_TYPE (intype))),
5158 build_pointer_type (TYPE_MAIN_VARIANT
5159 (TREE_TYPE (type)))))
5164 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5165 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5166 c_cast_p ? ba_unique : ba_check,
5168 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5171 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5172 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5179 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5180 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5182 if (TYPE_PTRMEM_P (type))
5184 t1 = (build_ptrmem_type
5186 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5187 t2 = (build_ptrmem_type
5189 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5196 if (can_convert (t1, t2) || can_convert (t2, t1))
5199 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5200 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5205 /* [expr.static.cast]
5207 An rvalue of type "pointer to cv void" can be explicitly
5208 converted to a pointer to object type. A value of type pointer
5209 to object converted to "pointer to cv void" and back to the
5210 original pointer type will have its original value. */
5211 if (TREE_CODE (intype) == POINTER_TYPE
5212 && VOID_TYPE_P (TREE_TYPE (intype))
5213 && TYPE_PTROB_P (type))
5216 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5217 return build_nop (type, expr);
5221 return error_mark_node;
5224 /* Return an expression representing static_cast<TYPE>(EXPR). */
5227 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5232 if (type == error_mark_node || expr == error_mark_node)
5233 return error_mark_node;
5235 if (processing_template_decl)
5237 expr = build_min (STATIC_CAST_EXPR, type, expr);
5238 /* We don't know if it will or will not have side effects. */
5239 TREE_SIDE_EFFECTS (expr) = 1;
5240 return convert_from_reference (expr);
5243 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5244 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5245 if (TREE_CODE (type) != REFERENCE_TYPE
5246 && TREE_CODE (expr) == NOP_EXPR
5247 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5248 expr = TREE_OPERAND (expr, 0);
5250 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5255 if (complain & tf_error)
5256 error ("invalid static_cast from type %qT to type %qT",
5257 TREE_TYPE (expr), type);
5258 return error_mark_node;
5261 /* EXPR is an expression with member function or pointer-to-member
5262 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5263 not permitted by ISO C++, but we accept it in some modes. If we
5264 are not in one of those modes, issue a diagnostic. Return the
5265 converted expression. */
5268 convert_member_func_to_ptr (tree type, tree expr)
5273 intype = TREE_TYPE (expr);
5274 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5275 || TREE_CODE (intype) == METHOD_TYPE);
5277 if (pedantic || warn_pmf2ptr)
5278 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpmf_conversions,
5279 "converting from %qT to %qT", intype, type);
5281 if (TREE_CODE (intype) == METHOD_TYPE)
5282 expr = build_addr_func (expr);
5283 else if (TREE_CODE (expr) == PTRMEM_CST)
5284 expr = build_address (PTRMEM_CST_MEMBER (expr));
5287 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5288 decl = build_address (decl);
5289 expr = get_member_function_from_ptrfunc (&decl, expr);
5292 return build_nop (type, expr);
5295 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5296 If C_CAST_P is true, this reinterpret cast is being done as part of
5297 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5298 indicate whether or not reinterpret_cast was valid. */
5301 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5302 bool *valid_p, tsubst_flags_t complain)
5306 /* Assume the cast is invalid. */
5310 if (type == error_mark_node || error_operand_p (expr))
5311 return error_mark_node;
5313 intype = TREE_TYPE (expr);
5315 /* Save casted types in the function's used types hash table. */
5316 used_types_insert (type);
5318 /* [expr.reinterpret.cast]
5319 An lvalue expression of type T1 can be cast to the type
5320 "reference to T2" if an expression of type "pointer to T1" can be
5321 explicitly converted to the type "pointer to T2" using a
5322 reinterpret_cast. */
5323 if (TREE_CODE (type) == REFERENCE_TYPE)
5325 if (! real_lvalue_p (expr))
5327 if (complain & tf_error)
5328 error ("invalid cast of an rvalue expression of type "
5331 return error_mark_node;
5334 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5335 "B" are related class types; the reinterpret_cast does not
5336 adjust the pointer. */
5337 if (TYPE_PTR_P (intype)
5338 && (complain & tf_warning)
5339 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5340 COMPARE_BASE | COMPARE_DERIVED)))
5341 warning (0, "casting %qT to %qT does not dereference pointer",
5344 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
5345 if (expr != error_mark_node)
5346 expr = build_reinterpret_cast_1
5347 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5349 if (expr != error_mark_node)
5350 expr = cp_build_indirect_ref (expr, 0, complain);
5354 /* As a G++ extension, we consider conversions from member
5355 functions, and pointers to member functions to
5356 pointer-to-function and pointer-to-void types. If
5357 -Wno-pmf-conversions has not been specified,
5358 convert_member_func_to_ptr will issue an error message. */
5359 if ((TYPE_PTRMEMFUNC_P (intype)
5360 || TREE_CODE (intype) == METHOD_TYPE)
5361 && TYPE_PTR_P (type)
5362 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5363 || VOID_TYPE_P (TREE_TYPE (type))))
5364 return convert_member_func_to_ptr (type, expr);
5366 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5367 array-to-pointer, and function-to-pointer conversions are
5369 expr = decay_conversion (expr);
5371 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5372 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5373 if (TREE_CODE (expr) == NOP_EXPR
5374 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5375 expr = TREE_OPERAND (expr, 0);
5377 if (error_operand_p (expr))
5378 return error_mark_node;
5380 intype = TREE_TYPE (expr);
5382 /* [expr.reinterpret.cast]
5383 A pointer can be converted to any integral type large enough to
5385 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5387 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5389 if (complain & tf_error)
5390 permerror (input_location, "cast from %qT to %qT loses precision",
5393 return error_mark_node;
5396 /* [expr.reinterpret.cast]
5397 A value of integral or enumeration type can be explicitly
5398 converted to a pointer. */
5399 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5402 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5403 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5404 return fold_if_not_in_template (build_nop (type, expr));
5405 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5406 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5411 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
5412 /* Warn about possible alignment problems. */
5413 if (STRICT_ALIGNMENT && warn_cast_align
5414 && (complain & tf_warning)
5415 && !VOID_TYPE_P (type)
5416 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5417 && COMPLETE_TYPE_P (TREE_TYPE (type))
5418 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5419 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5420 warning (OPT_Wcast_align, "cast from %qT to %qT "
5421 "increases required alignment of target type", intype, type);
5423 /* We need to strip nops here, because the front end likes to
5424 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5426 if (warn_strict_aliasing <= 2)
5427 strict_aliasing_warning (intype, type, sexpr);
5429 return fold_if_not_in_template (build_nop (type, expr));
5431 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5432 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5434 if (pedantic && (complain & tf_warning))
5435 /* Only issue a warning, as we have always supported this
5436 where possible, and it is necessary in some cases. DR 195
5437 addresses this issue, but as of 2004/10/26 is still in
5439 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5440 return fold_if_not_in_template (build_nop (type, expr));
5442 else if (TREE_CODE (type) == VECTOR_TYPE)
5443 return fold_if_not_in_template (convert_to_vector (type, expr));
5444 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5445 return fold_if_not_in_template (convert_to_integer (type, expr));
5450 if (complain & tf_error)
5451 error ("invalid cast from type %qT to type %qT", intype, type);
5452 return error_mark_node;
5455 return cp_convert (type, expr);
5459 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
5461 if (type == error_mark_node || expr == error_mark_node)
5462 return error_mark_node;
5464 if (processing_template_decl)
5466 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5468 if (!TREE_SIDE_EFFECTS (t)
5469 && type_dependent_expression_p (expr))
5470 /* There might turn out to be side effects inside expr. */
5471 TREE_SIDE_EFFECTS (t) = 1;
5472 return convert_from_reference (t);
5475 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5476 /*valid_p=*/NULL, complain);
5479 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5480 return an appropriate expression. Otherwise, return
5481 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5482 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5483 performing a C-style cast, its value upon return will indicate
5484 whether or not the conversion succeeded. */
5487 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5491 tree reference_type;
5493 /* Callers are responsible for handling error_mark_node as a
5494 destination type. */
5495 gcc_assert (dst_type != error_mark_node);
5496 /* In a template, callers should be building syntactic
5497 representations of casts, not using this machinery. */
5498 gcc_assert (!processing_template_decl);
5500 /* Assume the conversion is invalid. */
5504 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5507 error ("invalid use of const_cast with type %qT, "
5508 "which is not a pointer, "
5509 "reference, nor a pointer-to-data-member type", dst_type);
5510 return error_mark_node;
5513 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5516 error ("invalid use of const_cast with type %qT, which is a pointer "
5517 "or reference to a function type", dst_type);
5518 return error_mark_node;
5521 /* Save casted types in the function's used types hash table. */
5522 used_types_insert (dst_type);
5524 src_type = TREE_TYPE (expr);
5525 /* Expressions do not really have reference types. */
5526 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5527 src_type = TREE_TYPE (src_type);
5529 /* [expr.const.cast]
5531 An lvalue of type T1 can be explicitly converted to an lvalue of
5532 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5533 types) if a pointer to T1 can be explicitly converted to the type
5534 pointer to T2 using a const_cast. */
5535 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5537 reference_type = dst_type;
5538 if (! real_lvalue_p (expr))
5541 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5542 src_type, dst_type);
5543 return error_mark_node;
5545 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5546 src_type = build_pointer_type (src_type);
5550 reference_type = NULL_TREE;
5551 /* If the destination type is not a reference type, the
5552 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5553 conversions are performed. */
5554 src_type = type_decays_to (src_type);
5555 if (src_type == error_mark_node)
5556 return error_mark_node;
5559 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5560 && comp_ptr_ttypes_const (dst_type, src_type))
5565 /* This cast is actually a C-style cast. Issue a warning if
5566 the user is making a potentially unsafe cast. */
5567 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
5571 expr = cp_build_unary_op (ADDR_EXPR, expr, 0,
5572 complain? tf_warning_or_error : tf_none);
5573 expr = build_nop (reference_type, expr);
5574 return convert_from_reference (expr);
5578 expr = decay_conversion (expr);
5579 /* build_c_cast puts on a NOP_EXPR to make the result not an
5580 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5581 non-lvalue context. */
5582 if (TREE_CODE (expr) == NOP_EXPR
5583 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5584 expr = TREE_OPERAND (expr, 0);
5585 return build_nop (dst_type, expr);
5590 error ("invalid const_cast from type %qT to type %qT",
5591 src_type, dst_type);
5592 return error_mark_node;
5596 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
5598 if (type == error_mark_node || error_operand_p (expr))
5599 return error_mark_node;
5601 if (processing_template_decl)
5603 tree t = build_min (CONST_CAST_EXPR, type, expr);
5605 if (!TREE_SIDE_EFFECTS (t)
5606 && type_dependent_expression_p (expr))
5607 /* There might turn out to be side effects inside expr. */
5608 TREE_SIDE_EFFECTS (t) = 1;
5609 return convert_from_reference (t);
5612 return build_const_cast_1 (type, expr, complain & tf_error,
5616 /* Like cp_build_c_cast, but for the c-common bits. */
5619 build_c_cast (tree type, tree expr)
5621 return cp_build_c_cast (type, expr, tf_warning_or_error);
5624 /* Build an expression representing an explicit C-style cast to type
5625 TYPE of expression EXPR. */
5628 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
5634 if (type == error_mark_node || error_operand_p (expr))
5635 return error_mark_node;
5637 if (processing_template_decl)
5639 tree t = build_min (CAST_EXPR, type,
5640 tree_cons (NULL_TREE, value, NULL_TREE));
5641 /* We don't know if it will or will not have side effects. */
5642 TREE_SIDE_EFFECTS (t) = 1;
5643 return convert_from_reference (t);
5646 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5647 'Class') should always be retained, because this information aids
5648 in method lookup. */
5649 if (objc_is_object_ptr (type)
5650 && objc_is_object_ptr (TREE_TYPE (expr)))
5651 return build_nop (type, expr);
5653 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5654 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5655 if (TREE_CODE (type) != REFERENCE_TYPE
5656 && TREE_CODE (value) == NOP_EXPR
5657 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5658 value = TREE_OPERAND (value, 0);
5660 if (TREE_CODE (type) == ARRAY_TYPE)
5662 /* Allow casting from T1* to T2[] because Cfront allows it.
5663 NIHCL uses it. It is not valid ISO C++ however. */
5664 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5666 if (complain & tf_error)
5667 permerror (input_location, "ISO C++ forbids casting to an array type %qT", type);
5669 return error_mark_node;
5670 type = build_pointer_type (TREE_TYPE (type));
5674 if (complain & tf_error)
5675 error ("ISO C++ forbids casting to an array type %qT", type);
5676 return error_mark_node;
5680 if (TREE_CODE (type) == FUNCTION_TYPE
5681 || TREE_CODE (type) == METHOD_TYPE)
5683 if (complain & tf_error)
5684 error ("invalid cast to function type %qT", type);
5685 return error_mark_node;
5688 /* A C-style cast can be a const_cast. */
5689 result = build_const_cast_1 (type, value, /*complain=*/false,
5694 /* Or a static cast. */
5695 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5696 &valid_p, complain);
5697 /* Or a reinterpret_cast. */
5699 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5700 &valid_p, complain);
5701 /* The static_cast or reinterpret_cast may be followed by a
5704 /* A valid cast may result in errors if, for example, a
5705 conversion to am ambiguous base class is required. */
5706 && !error_operand_p (result))
5710 /* Non-class rvalues always have cv-unqualified type. */
5711 if (!CLASS_TYPE_P (type))
5712 type = TYPE_MAIN_VARIANT (type);
5713 result_type = TREE_TYPE (result);
5714 if (!CLASS_TYPE_P (result_type))
5715 result_type = TYPE_MAIN_VARIANT (result_type);
5716 /* If the type of RESULT does not match TYPE, perform a
5717 const_cast to make it match. If the static_cast or
5718 reinterpret_cast succeeded, we will differ by at most
5719 cv-qualification, so the follow-on const_cast is guaranteed
5721 if (!same_type_p (non_reference (type), non_reference (result_type)))
5723 result = build_const_cast_1 (type, result, false, &valid_p);
5724 gcc_assert (valid_p);
5729 return error_mark_node;
5732 /* For use from the C common bits. */
5734 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5736 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
5739 /* Build an assignment expression of lvalue LHS from value RHS.
5740 MODIFYCODE is the code for a binary operator that we use
5741 to combine the old value of LHS with RHS to get the new value.
5742 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5744 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5747 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
5748 tsubst_flags_t complain)
5752 tree lhstype = TREE_TYPE (lhs);
5753 tree olhstype = lhstype;
5754 tree olhs = NULL_TREE;
5755 bool plain_assign = (modifycode == NOP_EXPR);
5757 /* Avoid duplicate error messages from operands that had errors. */
5758 if (error_operand_p (lhs) || error_operand_p (rhs))
5759 return error_mark_node;
5761 /* Handle control structure constructs used as "lvalues". */
5762 switch (TREE_CODE (lhs))
5764 /* Handle --foo = 5; as these are valid constructs in C++. */
5765 case PREDECREMENT_EXPR:
5766 case PREINCREMENT_EXPR:
5767 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5768 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5769 stabilize_reference (TREE_OPERAND (lhs, 0)),
5770 TREE_OPERAND (lhs, 1));
5771 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0),
5772 modifycode, rhs, complain);
5773 if (newrhs == error_mark_node)
5774 return error_mark_node;
5775 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5777 /* Handle (a, b) used as an "lvalue". */
5779 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5780 modifycode, rhs, complain);
5781 if (newrhs == error_mark_node)
5782 return error_mark_node;
5783 return build2 (COMPOUND_EXPR, lhstype,
5784 TREE_OPERAND (lhs, 0), newrhs);
5787 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5788 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5789 stabilize_reference (TREE_OPERAND (lhs, 0)),
5790 TREE_OPERAND (lhs, 1));
5791 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
5793 if (newrhs == error_mark_node)
5794 return error_mark_node;
5795 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5799 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5800 when neither operand has side-effects. */
5801 if (!lvalue_or_else (lhs, lv_assign, complain))
5802 return error_mark_node;
5804 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5805 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5807 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5808 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5810 TREE_OPERAND (lhs, 0),
5811 TREE_OPERAND (lhs, 1)),
5812 TREE_OPERAND (lhs, 0),
5813 TREE_OPERAND (lhs, 1));
5816 /* Handle (a ? b : c) used as an "lvalue". */
5819 /* Produce (a ? (b = rhs) : (c = rhs))
5820 except that the RHS goes through a save-expr
5821 so the code to compute it is only emitted once. */
5823 tree preeval = NULL_TREE;
5825 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5827 if (complain & tf_error)
5828 error ("void value not ignored as it ought to be");
5829 return error_mark_node;
5832 rhs = stabilize_expr (rhs, &preeval);
5834 /* Check this here to avoid odd errors when trying to convert
5835 a throw to the type of the COND_EXPR. */
5836 if (!lvalue_or_else (lhs, lv_assign, complain))
5837 return error_mark_node;
5839 cond = build_conditional_expr
5840 (TREE_OPERAND (lhs, 0),
5841 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5842 modifycode, rhs, complain),
5843 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
5844 modifycode, rhs, complain),
5847 if (cond == error_mark_node)
5849 /* Make sure the code to compute the rhs comes out
5850 before the split. */
5852 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5860 if (modifycode == INIT_EXPR)
5862 if (TREE_CODE (rhs) == CONSTRUCTOR)
5864 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5865 /* Call convert to generate an error; see PR 11063. */
5866 rhs = convert (lhstype, rhs);
5867 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5868 TREE_SIDE_EFFECTS (result) = 1;
5871 else if (! MAYBE_CLASS_TYPE_P (lhstype))
5872 /* Do the default thing. */;
5875 result = build_special_member_call (lhs, complete_ctor_identifier,
5876 build_tree_list (NULL_TREE, rhs),
5877 lhstype, LOOKUP_NORMAL,
5879 if (result == NULL_TREE)
5880 return error_mark_node;
5886 lhs = require_complete_type (lhs);
5887 if (lhs == error_mark_node)
5888 return error_mark_node;
5890 if (modifycode == NOP_EXPR)
5892 /* `operator=' is not an inheritable operator. */
5893 if (! MAYBE_CLASS_TYPE_P (lhstype))
5894 /* Do the default thing. */;
5897 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5898 lhs, rhs, make_node (NOP_EXPR),
5899 /*overloaded_p=*/NULL,
5901 if (result == NULL_TREE)
5902 return error_mark_node;
5909 /* A binary op has been requested. Combine the old LHS
5910 value with the RHS producing the value we should actually
5911 store into the LHS. */
5912 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
5913 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
5914 || MAYBE_CLASS_TYPE_P (lhstype)));
5916 lhs = stabilize_reference (lhs);
5917 newrhs = cp_build_binary_op (modifycode, lhs, rhs,
5919 if (newrhs == error_mark_node)
5921 if (complain & tf_error)
5922 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5923 TREE_TYPE (lhs), TREE_TYPE (rhs));
5924 return error_mark_node;
5927 /* Now it looks like a plain assignment. */
5928 modifycode = NOP_EXPR;
5930 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5931 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5934 /* The left-hand side must be an lvalue. */
5935 if (!lvalue_or_else (lhs, lv_assign, complain))
5936 return error_mark_node;
5938 /* Warn about modifying something that is `const'. Don't warn if
5939 this is initialization. */
5940 if (modifycode != INIT_EXPR
5941 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5942 /* Functions are not modifiable, even though they are
5944 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5945 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5946 /* If it's an aggregate and any field is const, then it is
5947 effectively const. */
5948 || (CLASS_TYPE_P (lhstype)
5949 && C_TYPE_FIELDS_READONLY (lhstype))))
5951 if (complain & tf_error)
5952 readonly_error (lhs, "assignment");
5954 return error_mark_node;
5957 /* If storing into a structure or union member, it has probably been
5958 given type `int'. Compute the type that would go with the actual
5959 amount of storage the member occupies. */
5961 if (TREE_CODE (lhs) == COMPONENT_REF
5962 && (TREE_CODE (lhstype) == INTEGER_TYPE
5963 || TREE_CODE (lhstype) == REAL_TYPE
5964 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5966 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5968 /* If storing in a field that is in actuality a short or narrower
5969 than one, we must store in the field in its actual type. */
5971 if (lhstype != TREE_TYPE (lhs))
5973 /* Avoid warnings converting integral types back into enums for
5975 if (TREE_CODE (lhstype) == INTEGER_TYPE
5976 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5978 if (TREE_SIDE_EFFECTS (lhs))
5979 lhs = stabilize_reference (lhs);
5982 lhs = copy_node (lhs);
5983 TREE_TYPE (lhs) = lhstype;
5987 /* Convert new value to destination type. */
5989 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5993 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5994 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5996 if (complain & tf_error)
5997 error ("incompatible types in assignment of %qT to %qT",
5998 TREE_TYPE (rhs), lhstype);
5999 return error_mark_node;
6002 /* Allow array assignment in compiler-generated code. */
6003 if (! DECL_ARTIFICIAL (current_function_decl))
6005 /* This routine is used for both initialization and assignment.
6006 Make sure the diagnostic message differentiates the context. */
6007 if (complain & tf_error)
6009 if (modifycode == INIT_EXPR)
6010 error ("array used as initializer");
6012 error ("invalid array assignment");
6014 return error_mark_node;
6017 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6018 ? 1 + (modifycode != INIT_EXPR): 0;
6019 return build_vec_init (lhs, NULL_TREE, newrhs,
6020 /*explicit_value_init_p=*/false,
6021 from_array, complain);
6024 if (modifycode == INIT_EXPR)
6025 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
6026 "initialization", NULL_TREE, 0,
6030 /* Avoid warnings on enum bit fields. */
6031 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
6032 && TREE_CODE (lhstype) == INTEGER_TYPE)
6034 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
6035 NULL_TREE, 0, complain);
6036 newrhs = convert_force (lhstype, newrhs, 0);
6039 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
6040 NULL_TREE, 0, complain);
6041 if (TREE_CODE (newrhs) == CALL_EXPR
6042 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6043 newrhs = build_cplus_new (lhstype, newrhs);
6045 /* Can't initialize directly from a TARGET_EXPR, since that would
6046 cause the lhs to be constructed twice, and possibly result in
6047 accidental self-initialization. So we force the TARGET_EXPR to be
6048 expanded without a target. */
6049 if (TREE_CODE (newrhs) == TARGET_EXPR)
6050 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6051 TREE_OPERAND (newrhs, 0));
6054 if (newrhs == error_mark_node)
6055 return error_mark_node;
6057 if (c_dialect_objc () && flag_objc_gc)
6059 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6065 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6066 lhstype, lhs, newrhs);
6068 TREE_SIDE_EFFECTS (result) = 1;
6070 TREE_NO_WARNING (result) = 1;
6072 /* If we got the LHS in a different type for storing in,
6073 convert the result back to the nominal type of LHS
6074 so that the value we return always has the same type
6075 as the LHS argument. */
6077 if (olhstype == TREE_TYPE (result))
6081 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6082 TREE_NO_WARNING (result) = 1;
6085 return convert_for_assignment (olhstype, result, "assignment",
6086 NULL_TREE, 0, complain);
6090 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6091 tsubst_flags_t complain)
6093 if (processing_template_decl)
6094 return build_min_nt (MODOP_EXPR, lhs,
6095 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6097 if (modifycode != NOP_EXPR)
6099 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6100 make_node (modifycode),
6101 /*overloaded_p=*/NULL,
6105 TREE_NO_WARNING (rval) = 1;
6109 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6112 /* Helper function for get_delta_difference which assumes FROM is a base
6113 class of TO. Returns a delta for the conversion of pointer-to-member
6114 of FROM to pointer-to-member of TO. If the conversion is invalid,
6115 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6116 If C_CAST_P is true, this conversion is taking place as part of a C-style
6120 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6125 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6126 if (kind == bk_inaccessible || kind == bk_ambig)
6128 error (" in pointer to member function conversion");
6129 return size_zero_node;
6133 if (kind != bk_via_virtual)
6134 return BINFO_OFFSET (binfo);
6136 /* FROM is a virtual base class of TO. Issue an error or warning
6137 depending on whether or not this is a reinterpret cast. */
6139 error ("pointer to member conversion via virtual base %qT",
6140 BINFO_TYPE (binfo_from_vbase (binfo)));
6142 return size_zero_node;
6149 /* Get difference in deltas for different pointer to member function
6150 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6151 the conversion is invalid, the constant is zero. If
6152 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6153 If C_CAST_P is true this conversion is taking place as part of a
6156 Note that the naming of FROM and TO is kind of backwards; the return
6157 value is what we add to a TO in order to get a FROM. They are named
6158 this way because we call this function to find out how to convert from
6159 a pointer to member of FROM to a pointer to member of TO. */
6162 get_delta_difference (tree from, tree to,
6163 bool allow_inverse_p,
6168 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6169 /* Pointer to member of incomplete class is permitted*/
6170 result = size_zero_node;
6172 result = get_delta_difference_1 (from, to, c_cast_p);
6176 if (!allow_inverse_p)
6178 error_not_base_type (from, to);
6179 error (" in pointer to member conversion");
6180 result = size_zero_node;
6184 result = get_delta_difference_1 (to, from, c_cast_p);
6187 result = size_diffop (size_zero_node, result);
6190 error_not_base_type (from, to);
6191 error (" in pointer to member conversion");
6192 result = size_zero_node;
6197 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6201 /* Return a constructor for the pointer-to-member-function TYPE using
6202 the other components as specified. */
6205 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6210 VEC(constructor_elt, gc) *v;
6212 /* Pull the FIELD_DECLs out of the type. */
6213 pfn_field = TYPE_FIELDS (type);
6214 delta_field = TREE_CHAIN (pfn_field);
6216 /* Make sure DELTA has the type we want. */
6217 delta = convert_and_check (delta_type_node, delta);
6219 /* Convert to the correct target type if necessary. */
6220 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6222 /* Finish creating the initializer. */
6223 v = VEC_alloc(constructor_elt, gc, 2);
6224 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6225 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6226 u = build_constructor (type, v);
6227 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6228 TREE_STATIC (u) = (TREE_CONSTANT (u)
6229 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6231 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6236 /* Build a constructor for a pointer to member function. It can be
6237 used to initialize global variables, local variable, or used
6238 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6241 If FORCE is nonzero, then force this conversion, even if
6242 we would rather not do it. Usually set when using an explicit
6243 cast. A C-style cast is being processed iff C_CAST_P is true.
6245 Return error_mark_node, if something goes wrong. */
6248 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6254 if (error_operand_p (pfn))
6255 return error_mark_node;
6257 pfn_type = TREE_TYPE (pfn);
6258 to_type = build_ptrmemfunc_type (type);
6260 /* Handle multiple conversions of pointer to member functions. */
6261 if (TYPE_PTRMEMFUNC_P (pfn_type))
6263 tree delta = NULL_TREE;
6264 tree npfn = NULL_TREE;
6268 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6269 error ("invalid conversion to type %qT from type %qT",
6272 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6273 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6277 /* We don't have to do any conversion to convert a
6278 pointer-to-member to its own type. But, we don't want to
6279 just return a PTRMEM_CST if there's an explicit cast; that
6280 cast should make the expression an invalid template argument. */
6281 if (TREE_CODE (pfn) != PTRMEM_CST)
6283 if (same_type_p (to_type, pfn_type))
6285 else if (integer_zerop (n))
6286 return build_reinterpret_cast (to_type, pfn,
6287 tf_warning_or_error);
6290 if (TREE_SIDE_EFFECTS (pfn))
6291 pfn = save_expr (pfn);
6293 /* Obtain the function pointer and the current DELTA. */
6294 if (TREE_CODE (pfn) == PTRMEM_CST)
6295 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6298 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6299 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6302 /* Just adjust the DELTA field. */
6303 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6304 (TREE_TYPE (delta), ptrdiff_type_node));
6305 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6306 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node,
6307 tf_warning_or_error);
6308 delta = cp_build_binary_op (PLUS_EXPR, delta, n, tf_warning_or_error);
6309 return build_ptrmemfunc1 (to_type, delta, npfn);
6312 /* Handle null pointer to member function conversions. */
6313 if (integer_zerop (pfn))
6315 pfn = build_c_cast (type, integer_zero_node);
6316 return build_ptrmemfunc1 (to_type,
6321 if (type_unknown_p (pfn))
6322 return instantiate_type (type, pfn, tf_warning_or_error);
6324 fn = TREE_OPERAND (pfn, 0);
6325 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6326 /* In a template, we will have preserved the
6328 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6329 return make_ptrmem_cst (to_type, fn);
6332 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6335 ??? There is no consistency as to the types returned for the above
6336 values. Some code acts as if it were a sizetype and some as if it were
6337 integer_type_node. */
6340 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6342 tree type = TREE_TYPE (cst);
6343 tree fn = PTRMEM_CST_MEMBER (cst);
6344 tree ptr_class, fn_class;
6346 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6348 /* The class that the function belongs to. */
6349 fn_class = DECL_CONTEXT (fn);
6351 /* The class that we're creating a pointer to member of. */
6352 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6354 /* First, calculate the adjustment to the function's class. */
6355 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6358 if (!DECL_VIRTUAL_P (fn))
6359 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6362 /* If we're dealing with a virtual function, we have to adjust 'this'
6363 again, to point to the base which provides the vtable entry for
6364 fn; the call will do the opposite adjustment. */
6365 tree orig_class = DECL_CONTEXT (fn);
6366 tree binfo = binfo_or_else (orig_class, fn_class);
6367 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6368 *delta, BINFO_OFFSET (binfo));
6369 *delta = fold_if_not_in_template (*delta);
6371 /* We set PFN to the vtable offset at which the function can be
6372 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6373 case delta is shifted left, and then incremented). */
6374 *pfn = DECL_VINDEX (fn);
6375 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6376 TYPE_SIZE_UNIT (vtable_entry_type));
6377 *pfn = fold_if_not_in_template (*pfn);
6379 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6381 case ptrmemfunc_vbit_in_pfn:
6382 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6384 *pfn = fold_if_not_in_template (*pfn);
6387 case ptrmemfunc_vbit_in_delta:
6388 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6389 *delta, integer_one_node);
6390 *delta = fold_if_not_in_template (*delta);
6391 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6392 *delta, integer_one_node);
6393 *delta = fold_if_not_in_template (*delta);
6400 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6401 *pfn = fold_if_not_in_template (*pfn);
6405 /* Return an expression for PFN from the pointer-to-member function
6409 pfn_from_ptrmemfunc (tree t)
6411 if (TREE_CODE (t) == PTRMEM_CST)
6416 expand_ptrmemfunc_cst (t, &delta, &pfn);
6421 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6424 /* Return an expression for DELTA from the pointer-to-member function
6428 delta_from_ptrmemfunc (tree t)
6430 if (TREE_CODE (t) == PTRMEM_CST)
6435 expand_ptrmemfunc_cst (t, &delta, &pfn);
6440 return build_ptrmemfunc_access_expr (t, delta_identifier);
6443 /* Convert value RHS to type TYPE as preparation for an assignment to
6444 an lvalue of type TYPE. ERRTYPE is a string to use in error
6445 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6446 are doing the conversion in order to pass the PARMNUMth argument of
6450 convert_for_assignment (tree type, tree rhs,
6451 const char *errtype, tree fndecl, int parmnum,
6452 tsubst_flags_t complain)
6455 enum tree_code coder;
6457 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6458 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6459 rhs = TREE_OPERAND (rhs, 0);
6461 rhstype = TREE_TYPE (rhs);
6462 coder = TREE_CODE (rhstype);
6464 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6465 && vector_types_convertible_p (type, rhstype, true))
6466 return convert (type, rhs);
6468 if (rhs == error_mark_node || rhstype == error_mark_node)
6469 return error_mark_node;
6470 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6471 return error_mark_node;
6473 /* The RHS of an assignment cannot have void type. */
6474 if (coder == VOID_TYPE)
6476 if (complain & tf_error)
6477 error ("void value not ignored as it ought to be");
6478 return error_mark_node;
6481 /* Simplify the RHS if possible. */
6482 if (TREE_CODE (rhs) == CONST_DECL)
6483 rhs = DECL_INITIAL (rhs);
6485 if (c_dialect_objc ())
6488 tree rname = fndecl;
6490 if (!strcmp (errtype, "assignment"))
6492 else if (!strcmp (errtype, "initialization"))
6496 tree selector = objc_message_selector ();
6500 if (selector && parmno > 1)
6507 if (objc_compare_types (type, rhstype, parmno, rname))
6508 return convert (type, rhs);
6513 The expression is implicitly converted (clause _conv_) to the
6514 cv-unqualified type of the left operand.
6516 We allow bad conversions here because by the time we get to this point
6517 we are committed to doing the conversion. If we end up doing a bad
6518 conversion, convert_like will complain. */
6519 if (!can_convert_arg_bad (type, rhstype, rhs))
6521 /* When -Wno-pmf-conversions is use, we just silently allow
6522 conversions from pointers-to-members to plain pointers. If
6523 the conversion doesn't work, cp_convert will complain. */
6525 && TYPE_PTR_P (type)
6526 && TYPE_PTRMEMFUNC_P (rhstype))
6527 rhs = cp_convert (strip_top_quals (type), rhs);
6530 if (complain & tf_error)
6532 /* If the right-hand side has unknown type, then it is an
6533 overloaded function. Call instantiate_type to get error
6535 if (rhstype == unknown_type_node)
6536 instantiate_type (type, rhs, tf_warning_or_error);
6538 error ("cannot convert %qT to %qT for argument %qP to %qD",
6539 rhstype, type, parmnum, fndecl);
6541 error ("cannot convert %qT to %qT in %s", rhstype, type,
6544 return error_mark_node;
6547 if (warn_missing_format_attribute)
6549 const enum tree_code codel = TREE_CODE (type);
6550 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6552 && check_missing_format_attribute (type, rhstype)
6553 && (complain & tf_warning))
6554 warning (OPT_Wmissing_format_attribute,
6555 "%s might be a candidate for a format attribute",
6559 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6561 if (warn_parentheses
6562 && type == boolean_type_node
6563 && TREE_CODE (rhs) == MODIFY_EXPR
6564 && !TREE_NO_WARNING (rhs)
6565 && TREE_TYPE (rhs) != boolean_type_node
6566 && (complain & tf_warning))
6568 warning (OPT_Wparentheses,
6569 "suggest parentheses around assignment used as truth value");
6570 TREE_NO_WARNING (rhs) = 1;
6573 return perform_implicit_conversion (strip_top_quals (type), rhs, complain);
6576 /* Convert RHS to be of type TYPE.
6577 If EXP is nonzero, it is the target of the initialization.
6578 ERRTYPE is a string to use in error messages.
6580 Two major differences between the behavior of
6581 `convert_for_assignment' and `convert_for_initialization'
6582 are that references are bashed in the former, while
6583 copied in the latter, and aggregates are assigned in
6584 the former (operator=) while initialized in the
6587 If using constructor make sure no conversion operator exists, if one does
6588 exist, an ambiguity exists.
6590 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6593 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6594 const char *errtype, tree fndecl, int parmnum,
6595 tsubst_flags_t complain)
6597 enum tree_code codel = TREE_CODE (type);
6599 enum tree_code coder;
6601 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6602 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6603 if (TREE_CODE (rhs) == NOP_EXPR
6604 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6605 && codel != REFERENCE_TYPE)
6606 rhs = TREE_OPERAND (rhs, 0);
6608 if (type == error_mark_node
6609 || rhs == error_mark_node
6610 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6611 return error_mark_node;
6613 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6614 && TREE_CODE (type) != ARRAY_TYPE
6615 && (TREE_CODE (type) != REFERENCE_TYPE
6616 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6617 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6618 && (TREE_CODE (type) != REFERENCE_TYPE
6619 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6620 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6621 rhs = decay_conversion (rhs);
6623 rhstype = TREE_TYPE (rhs);
6624 coder = TREE_CODE (rhstype);
6626 if (coder == ERROR_MARK)
6627 return error_mark_node;
6629 /* We accept references to incomplete types, so we can
6630 return here before checking if RHS is of complete type. */
6632 if (codel == REFERENCE_TYPE)
6634 /* This should eventually happen in convert_arguments. */
6635 int savew = 0, savee = 0;
6638 savew = warningcount, savee = errorcount;
6639 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6643 if (warningcount > savew)
6644 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6645 else if (errorcount > savee)
6646 error ("in passing argument %P of %q+D", parmnum, fndecl);
6652 exp = require_complete_type (exp);
6653 if (exp == error_mark_node)
6654 return error_mark_node;
6656 rhstype = non_reference (rhstype);
6658 type = complete_type (type);
6660 if (MAYBE_CLASS_TYPE_P (type))
6661 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6663 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
6667 /* If RETVAL is the address of, or a reference to, a local variable or
6668 temporary give an appropriate warning. */
6671 maybe_warn_about_returning_address_of_local (tree retval)
6673 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6674 tree whats_returned = retval;
6678 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6679 whats_returned = TREE_OPERAND (whats_returned, 1);
6680 else if (CONVERT_EXPR_P (whats_returned)
6681 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR)
6682 whats_returned = TREE_OPERAND (whats_returned, 0);
6687 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6689 whats_returned = TREE_OPERAND (whats_returned, 0);
6691 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6693 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6694 || TREE_CODE (whats_returned) == TARGET_EXPR)
6696 warning (0, "returning reference to temporary");
6699 if (TREE_CODE (whats_returned) == VAR_DECL
6700 && DECL_NAME (whats_returned)
6701 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6703 warning (0, "reference to non-lvalue returned");
6708 while (TREE_CODE (whats_returned) == COMPONENT_REF
6709 || TREE_CODE (whats_returned) == ARRAY_REF)
6710 whats_returned = TREE_OPERAND (whats_returned, 0);
6712 if (DECL_P (whats_returned)
6713 && DECL_NAME (whats_returned)
6714 && DECL_FUNCTION_SCOPE_P (whats_returned)
6715 && !(TREE_STATIC (whats_returned)
6716 || TREE_PUBLIC (whats_returned)))
6718 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6719 warning (0, "reference to local variable %q+D returned",
6722 warning (0, "address of local variable %q+D returned",
6728 /* Check that returning RETVAL from the current function is valid.
6729 Return an expression explicitly showing all conversions required to
6730 change RETVAL into the function return type, and to assign it to
6731 the DECL_RESULT for the function. Set *NO_WARNING to true if
6732 code reaches end of non-void function warning shouldn't be issued
6733 on this RETURN_EXPR. */
6736 check_return_expr (tree retval, bool *no_warning)
6739 /* The type actually returned by the function, after any
6742 int fn_returns_value_p;
6743 bool named_return_value_okay_p;
6745 *no_warning = false;
6747 /* A `volatile' function is one that isn't supposed to return, ever.
6748 (This is a G++ extension, used to get better code for functions
6749 that call the `volatile' function.) */
6750 if (TREE_THIS_VOLATILE (current_function_decl))
6751 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6753 /* Check for various simple errors. */
6754 if (DECL_DESTRUCTOR_P (current_function_decl))
6757 error ("returning a value from a destructor");
6760 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6762 if (in_function_try_handler)
6763 /* If a return statement appears in a handler of the
6764 function-try-block of a constructor, the program is ill-formed. */
6765 error ("cannot return from a handler of a function-try-block of a constructor");
6767 /* You can't return a value from a constructor. */
6768 error ("returning a value from a constructor");
6772 if (processing_template_decl)
6774 current_function_returns_value = 1;
6775 if (check_for_bare_parameter_packs (retval))
6776 retval = error_mark_node;
6780 /* When no explicit return-value is given in a function with a named
6781 return value, the named return value is used. */
6782 result = DECL_RESULT (current_function_decl);
6783 valtype = TREE_TYPE (result);
6784 gcc_assert (valtype != NULL_TREE);
6785 fn_returns_value_p = !VOID_TYPE_P (valtype);
6786 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6789 /* Check for a return statement with no return value in a function
6790 that's supposed to return a value. */
6791 if (!retval && fn_returns_value_p)
6793 permerror (input_location, "return-statement with no value, in function returning %qT",
6795 /* Clear this, so finish_function won't say that we reach the
6796 end of a non-void function (which we don't, we gave a
6798 current_function_returns_null = 0;
6799 /* And signal caller that TREE_NO_WARNING should be set on the
6800 RETURN_EXPR to avoid control reaches end of non-void function
6801 warnings in tree-cfg.c. */
6804 /* Check for a return statement with a value in a function that
6805 isn't supposed to return a value. */
6806 else if (retval && !fn_returns_value_p)
6808 if (VOID_TYPE_P (TREE_TYPE (retval)))
6809 /* You can return a `void' value from a function of `void'
6810 type. In that case, we have to evaluate the expression for
6811 its side-effects. */
6812 finish_expr_stmt (retval);
6814 permerror (input_location, "return-statement with a value, in function "
6815 "returning 'void'");
6816 current_function_returns_null = 1;
6818 /* There's really no value to return, after all. */
6822 /* Remember that this function can sometimes return without a
6824 current_function_returns_null = 1;
6826 /* Remember that this function did return a value. */
6827 current_function_returns_value = 1;
6829 /* Check for erroneous operands -- but after giving ourselves a
6830 chance to provide an error about returning a value from a void
6832 if (error_operand_p (retval))
6834 current_function_return_value = error_mark_node;
6835 return error_mark_node;
6838 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6839 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6840 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6841 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6843 && retval && null_ptr_cst_p (retval))
6844 warning (0, "%<operator new%> must not return NULL unless it is "
6845 "declared %<throw()%> (or -fcheck-new is in effect)");
6847 /* Effective C++ rule 15. See also start_function. */
6849 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6853 /* The function return type must be a reference to the current
6855 if (TREE_CODE (valtype) == REFERENCE_TYPE
6856 && same_type_ignoring_top_level_qualifiers_p
6857 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6859 /* Returning '*this' is obviously OK. */
6860 if (retval == current_class_ref)
6862 /* If we are calling a function whose return type is the same of
6863 the current class reference, it is ok. */
6864 else if (TREE_CODE (retval) == INDIRECT_REF
6865 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6870 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6873 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6875 [...] For a function with a class return type, if the expression
6876 in the return statement is the name of a local object, and the cv-
6877 unqualified type of the local object is the same as the function
6878 return type, an implementation is permitted to omit creating the tem-
6879 porary object to hold the function return value [...]
6881 So, if this is a value-returning function that always returns the same
6882 local variable, remember it.
6884 It might be nice to be more flexible, and choose the first suitable
6885 variable even if the function sometimes returns something else, but
6886 then we run the risk of clobbering the variable we chose if the other
6887 returned expression uses the chosen variable somehow. And people expect
6888 this restriction, anyway. (jason 2000-11-19)
6890 See finish_function and finalize_nrv for the rest of this optimization. */
6892 named_return_value_okay_p =
6893 (retval != NULL_TREE
6894 /* Must be a local, automatic variable. */
6895 && TREE_CODE (retval) == VAR_DECL
6896 && DECL_CONTEXT (retval) == current_function_decl
6897 && ! TREE_STATIC (retval)
6898 && ! DECL_ANON_UNION_VAR_P (retval)
6899 && (DECL_ALIGN (retval)
6900 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6901 /* The cv-unqualified type of the returned value must be the
6902 same as the cv-unqualified return type of the
6904 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6906 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
6907 /* And the returned value must be non-volatile. */
6908 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
6910 if (fn_returns_value_p && flag_elide_constructors)
6912 if (named_return_value_okay_p
6913 && (current_function_return_value == NULL_TREE
6914 || current_function_return_value == retval))
6915 current_function_return_value = retval;
6917 current_function_return_value = error_mark_node;
6920 /* We don't need to do any conversions when there's nothing being
6925 /* Do any required conversions. */
6926 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6927 /* No conversions are required. */
6931 /* The type the function is declared to return. */
6932 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6933 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6935 /* The functype's return type will have been set to void, if it
6936 was an incomplete type. Just treat this as 'return;' */
6937 if (VOID_TYPE_P (functype))
6938 return error_mark_node;
6940 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6941 treated as an rvalue for the purposes of overload resolution to
6942 favor move constructors over copy constructors. */
6943 if ((cxx_dialect != cxx98)
6944 && named_return_value_okay_p
6945 /* The variable must not have the `volatile' qualifier. */
6946 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6947 /* The return type must be a class type. */
6948 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6949 flags = flags | LOOKUP_PREFER_RVALUE;
6951 /* First convert the value to the function's return type, then
6952 to the type of return value's location to handle the
6953 case that functype is smaller than the valtype. */
6954 retval = convert_for_initialization
6955 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0,
6956 tf_warning_or_error);
6957 retval = convert (valtype, retval);
6959 /* If the conversion failed, treat this just like `return;'. */
6960 if (retval == error_mark_node)
6962 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6963 else if (! cfun->returns_struct
6964 && TREE_CODE (retval) == TARGET_EXPR
6965 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6966 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6967 TREE_OPERAND (retval, 0));
6969 maybe_warn_about_returning_address_of_local (retval);
6972 /* Actually copy the value returned into the appropriate location. */
6973 if (retval && retval != result)
6974 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6980 /* Returns nonzero if the pointer-type FROM can be converted to the
6981 pointer-type TO via a qualification conversion. If CONSTP is -1,
6982 then we return nonzero if the pointers are similar, and the
6983 cv-qualification signature of FROM is a proper subset of that of TO.
6985 If CONSTP is positive, then all outer pointers have been
6989 comp_ptr_ttypes_real (tree to, tree from, int constp)
6991 bool to_more_cv_qualified = false;
6992 bool is_opaque_pointer = false;
6994 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6996 if (TREE_CODE (to) != TREE_CODE (from))
6999 if (TREE_CODE (from) == OFFSET_TYPE
7000 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7001 TYPE_OFFSET_BASETYPE (to)))
7004 /* Const and volatile mean something different for function types,
7005 so the usual checks are not appropriate. */
7006 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7008 /* In Objective-C++, some types may have been 'volatilized' by
7009 the compiler for EH; when comparing them here, the volatile
7010 qualification must be ignored. */
7011 bool objc_quals_match = objc_type_quals_match (to, from);
7013 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7016 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7020 to_more_cv_qualified = true;
7024 constp &= TYPE_READONLY (to);
7027 if (TREE_CODE (to) == VECTOR_TYPE)
7028 is_opaque_pointer = vector_targets_convertible_p (to, from);
7030 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7031 return ((constp >= 0 || to_more_cv_qualified)
7032 && (is_opaque_pointer
7033 || same_type_ignoring_top_level_qualifiers_p (to, from)));
7037 /* When comparing, say, char ** to char const **, this function takes
7038 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7039 types to this function. */
7042 comp_ptr_ttypes (tree to, tree from)
7044 return comp_ptr_ttypes_real (to, from, 1);
7047 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7048 type or inheritance-related types, regardless of cv-quals. */
7051 ptr_reasonably_similar (const_tree to, const_tree from)
7053 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7055 /* Any target type is similar enough to void. */
7056 if (TREE_CODE (to) == VOID_TYPE
7057 || TREE_CODE (from) == VOID_TYPE)
7060 if (TREE_CODE (to) != TREE_CODE (from))
7063 if (TREE_CODE (from) == OFFSET_TYPE
7064 && comptypes (TYPE_OFFSET_BASETYPE (to),
7065 TYPE_OFFSET_BASETYPE (from),
7066 COMPARE_BASE | COMPARE_DERIVED))
7069 if (TREE_CODE (to) == VECTOR_TYPE
7070 && vector_types_convertible_p (to, from, false))
7073 if (TREE_CODE (to) == INTEGER_TYPE
7074 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7077 if (TREE_CODE (to) == FUNCTION_TYPE)
7080 if (TREE_CODE (to) != POINTER_TYPE)
7082 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7083 COMPARE_BASE | COMPARE_DERIVED);
7087 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7088 pointer-to-member types) are the same, ignoring cv-qualification at
7092 comp_ptr_ttypes_const (tree to, tree from)
7094 bool is_opaque_pointer = false;
7096 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7098 if (TREE_CODE (to) != TREE_CODE (from))
7101 if (TREE_CODE (from) == OFFSET_TYPE
7102 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7103 TYPE_OFFSET_BASETYPE (to)))
7106 if (TREE_CODE (to) == VECTOR_TYPE)
7107 is_opaque_pointer = vector_targets_convertible_p (to, from);
7109 if (TREE_CODE (to) != POINTER_TYPE)
7110 return (is_opaque_pointer
7111 || same_type_ignoring_top_level_qualifiers_p (to, from));
7115 /* Returns the type qualifiers for this type, including the qualifiers on the
7116 elements for an array type. */
7119 cp_type_quals (const_tree type)
7121 /* This CONST_CAST is okay because strip_array_types returns its
7122 argument unmodified and we assign it to a const_tree. */
7123 type = strip_array_types (CONST_CAST_TREE(type));
7124 if (type == error_mark_node)
7125 return TYPE_UNQUALIFIED;
7126 return TYPE_QUALS (type);
7129 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7133 cp_type_readonly (const_tree type)
7135 /* This CONST_CAST is okay because strip_array_types returns its
7136 argument unmodified and we assign it to a const_tree. */
7137 type = strip_array_types (CONST_CAST_TREE(type));
7138 return TYPE_READONLY (type);
7141 /* Returns nonzero if the TYPE contains a mutable member. */
7144 cp_has_mutable_p (const_tree type)
7146 /* This CONST_CAST is okay because strip_array_types returns its
7147 argument unmodified and we assign it to a const_tree. */
7148 type = strip_array_types (CONST_CAST_TREE(type));
7150 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7153 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7154 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7155 approximation. In particular, consider:
7158 struct S { int i; };
7159 const S s = { f(); }
7161 Here, we will make "s" as TREE_READONLY (because it is declared
7162 "const") -- only to reverse ourselves upon seeing that the
7163 initializer is non-constant. */
7166 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7168 tree type = TREE_TYPE (decl);
7170 if (type == error_mark_node)
7173 if (TREE_CODE (type) == FUNCTION_TYPE
7174 && type_quals != TYPE_UNQUALIFIED)
7176 /* This was an error in C++98 (cv-qualifiers cannot be added to
7177 a function type), but DR 295 makes the code well-formed by
7178 dropping the extra qualifiers. */
7181 tree bad_type = build_qualified_type (type, type_quals);
7182 pedwarn (input_location, OPT_pedantic,
7183 "ignoring %qV qualifiers added to function type %qT",
7187 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7191 /* Avoid setting TREE_READONLY incorrectly. */
7192 if (/* If the object has a constructor, the constructor may modify
7194 TYPE_NEEDS_CONSTRUCTING (type)
7195 /* If the type isn't complete, we don't know yet if it will need
7197 || !COMPLETE_TYPE_P (type)
7198 /* If the type has a mutable component, that component might be
7200 || TYPE_HAS_MUTABLE_P (type))
7201 type_quals &= ~TYPE_QUAL_CONST;
7203 c_apply_type_quals_to_decl (type_quals, decl);
7206 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7207 exemplar types such that casting T1 to T2 is casting away constness
7208 if and only if there is no implicit conversion from T1 to T2. */
7211 casts_away_constness_r (tree *t1, tree *t2)
7216 /* [expr.const.cast]
7218 For multi-level pointer to members and multi-level mixed pointers
7219 and pointers to members (conv.qual), the "member" aspect of a
7220 pointer to member level is ignored when determining if a const
7221 cv-qualifier has been cast away. */
7222 /* [expr.const.cast]
7224 For two pointer types:
7226 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7227 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7230 casting from X1 to X2 casts away constness if, for a non-pointer
7231 type T there does not exist an implicit conversion (clause
7234 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7238 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7239 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7240 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7242 *t1 = cp_build_qualified_type (void_type_node,
7243 cp_type_quals (*t1));
7244 *t2 = cp_build_qualified_type (void_type_node,
7245 cp_type_quals (*t2));
7249 quals1 = cp_type_quals (*t1);
7250 quals2 = cp_type_quals (*t2);
7252 if (TYPE_PTRMEM_P (*t1))
7253 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7255 *t1 = TREE_TYPE (*t1);
7256 if (TYPE_PTRMEM_P (*t2))
7257 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7259 *t2 = TREE_TYPE (*t2);
7261 casts_away_constness_r (t1, t2);
7262 *t1 = build_pointer_type (*t1);
7263 *t2 = build_pointer_type (*t2);
7264 *t1 = cp_build_qualified_type (*t1, quals1);
7265 *t2 = cp_build_qualified_type (*t2, quals2);
7268 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7272 casts_away_constness (tree t1, tree t2)
7274 if (TREE_CODE (t2) == REFERENCE_TYPE)
7276 /* [expr.const.cast]
7278 Casting from an lvalue of type T1 to an lvalue of type T2
7279 using a reference cast casts away constness if a cast from an
7280 rvalue of type "pointer to T1" to the type "pointer to T2"
7281 casts away constness. */
7282 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7283 return casts_away_constness (build_pointer_type (t1),
7284 build_pointer_type (TREE_TYPE (t2)));
7287 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7288 /* [expr.const.cast]
7290 Casting from an rvalue of type "pointer to data member of X
7291 of type T1" to the type "pointer to data member of Y of type
7292 T2" casts away constness if a cast from an rvalue of type
7293 "pointer to T1" to the type "pointer to T2" casts away
7295 return casts_away_constness
7296 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7297 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7299 /* Casting away constness is only something that makes sense for
7300 pointer or reference types. */
7301 if (TREE_CODE (t1) != POINTER_TYPE
7302 || TREE_CODE (t2) != POINTER_TYPE)
7305 /* Top-level qualifiers don't matter. */
7306 t1 = TYPE_MAIN_VARIANT (t1);
7307 t2 = TYPE_MAIN_VARIANT (t2);
7308 casts_away_constness_r (&t1, &t2);
7309 if (!can_convert (t2, t1))
7315 /* If T is a REFERENCE_TYPE return the type to which T refers.
7316 Otherwise, return T itself. */
7319 non_reference (tree t)
7321 if (TREE_CODE (t) == REFERENCE_TYPE)
7327 /* Return nonzero if REF is an lvalue valid for this language;
7328 otherwise, print an error message and return zero. USE says
7329 how the lvalue is being used and so selects the error message. */
7332 lvalue_or_else (const_tree ref, enum lvalue_use use, tsubst_flags_t complain)
7334 int win = lvalue_p (ref);
7336 if (!win && (complain & tf_error))